Including EMS Tromp Award for an outstanding achievement in biometeorology
In this context, the session will address issues concerning health, warning systems and measures in place to mitigate adverse impacts, and the models used to evaluate the heat load and cold stress on organisms. This will include the thermal component from the environment, weather sensitivity, actinic and chemical components of stress factors. Modelling studies and experimental studies on how environmental management, urban planning and design or traffic regulation can improve living conditions and decrease emissions are particularly welcome.
In addition, the session will consider the impacts of weather processes on human well-being and health. Since several methods are in use to compile bio-weather forecasts, we are looking forward to discussing such approaches and the way to convey such information to the public, but also to special target groups. Another aim is to describe ways, how climate data and information should be transferred and addressed for issues on tourism, recreation and other economic sectors.
The session will also address efforts to combine different environmental impacts on humans into one single index, as it is well known that humans react to the whole mix of atmospheric stimuli. Our aim is to improve the requested information and to look for more efficient ways of conveying the message on a regular basis in order to enable citizens to make the best use of such information in their everyday activities.
South Africa (SA) is highly vulnerable to the effects of drought on the environment, economy, and society. However, its effect on human health remains unclear. Understanding the mortality risk associated with different types of droughts in different population groups and by specific causes would help clarify the potential mechanisms involved. The study aims to comprehensively assess the effect of droughts of varying time scales on cause-specific mortality (all; infectious and parasitic; endocrine, nutritional, and metabolic; cardiovascular; respiratory) in SA (from 2009–2016) and identify more vulnerable profiles based on sex and age. We also evaluated the urbanicity and district-level socioeconomic deprivation as potential risk modifiers. We used a two-stage time-series study design, with the weekly standardized precipitation-evapotranspiration index (SPEI) calculated at 1, 6, 12, and 15 months of accumulation to identify droughts of different duration (SPEI1, 6, 12, 15, respectively). We applied a quasi-Poisson regression adjusted by mean temperature to assess the association between each type of drought and weekly mortality in all district municipalities of SA, and then pooled the estimates in a meta-regression model. We reported relative risks (RRs) for one unit increase of drought severity. Overall, we found a positive association between droughts (regardless the time scale) and all causes of death analyzed. The strongest associations were found for the drought events more prolonged (RR [95%CI]: 1.027 [1.018, 1.036] (SPEI1); 1.035 [1.021, 1.050] (SPEI6); 1.033 [1.008, 1.058] (SPEI12); 1.098 [1.068, 1.129] (SPEI15)) and respiratory mortality (RRs varied from 1.037 [1.021, 1.053] (SPEI1) to 1.189 [1.14, 1.241] (SPEI15)). An indication of greater vulnerability was found in younger adults for the shortest droughts, in older adults for medium-term and long-term droughts, and children for very long-term droughts. However, differences were not significant. Further evidence of the relevance of urbanicity and demographic and socioeconomic conditions as potential risk modifiers is needed.
How to cite: Salvador, C.: Analysing the effects of drought at different timescales on cause-specific mortality in South Africa, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-823, https://doi.org/10.5194/ems2026-823, 2026.
Climate change manifests not only as changes in daily mean temperatures but also as shifts in the time of day at which equivalent temperatures occur. These changes influence how people experience heat, when they can work safely, and when energy is needed to stay cool. We analyze historical analogues in the daily temperature cycle by comparing equivalent hourly temperatures since the 1980s. On a global average, temperatures characteristic of the morning warming period occur roughly 15 minutes earlier per decade, while those in the afternoon cooling period occur more than 20 minutes later per decade. For example, temperatures that occurred at 10 AM in the 1980s now occur at 9 AM, with even greater shifts in the afternoon. We extend this analysis to wet-bulb globe temperature (WBGT) to assess how shifts in timing translate to human-perceived heat stress, and find that these shifts are even larger in magnitude (minutes per decade). Across IPCC AR6 land regions, timing shifts scale with regional warming rates and diurnal temperature range, as stronger warming and smaller diurnal temperature ranges produce larger temporal displacements of equivalent temperatures. If sustained, these shifts would displace the time of day at which equivalent temperatures occur by more than three hours by 2100 relative to the 1980s, persisting under a pathway broadly consistent with recent emissions trends (SSP2-4.5) but slowing and eventually stopping under strong mitigation (SSP1-2.6). The timing changes perturb ecological cues, increase human heat exposure, and displace energy demand in ways not captured by means or extremes, underscoring the value of time-of-day metrics for characterizing climate change impacts.
How to cite: Shmuel, A., Greenspoon, L., Schleussner, C.-F., Mankin, J., and Milo, R.: The daily timing of a given temperature has shifted by over an hour since 1980, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-22, https://doi.org/10.5194/ems2026-22, 2026.
Urban heat intensification increasingly exacerbates outdoor thermal comfort, posing challenges for urban planning and climate adaptation. Shading and ventilation are recognized strategies to mitigate thermal stress. However, most studies rely on physical indicators without calibration to local subjective responses. In Taiwan’s hot-humid climate, such approaches may inadequately reflect actual comfort, and the interaction between ventilation and solar radiation remains insufficiently explored. Integrating subjective perceptions with environmental data is therefore critical to refine thermal comfort range and understand how shading and sun exposure modulate ventilation effects.
This study conducted field measurements (Air temperature, Globe temperature, Relative humidity, Wind speed) during the summer of 2025 at shaded and sun-exposed outdoor sites in Tainan, Taiwan. While simultaneously collecting participants’ personal characteristics and multi-dimensional subjective evaluations through questionnaire surveys, including Thermal Sensation Vote (TSV), Thermal Comfort Vote (TCV), Overall Comfort Vote (OCV), and environmental preference votes for temperature, wind, solar radiation, and humidity. Physiological Equivalent Temperature (PET) and mean radiant temperature (Tmrt) were calculated using RayMan Pro and ISO standard, respectively. Statistical analyses were then performed to examine discrepancies between objective physical conditions and subjective perceptions. Furthermore, considering human thermal adaptation under climate change, this study refines the conventional PET comfort range and establishes a localized assessment framework suitable for hot-humid environments.
Results indicate that shading effectively reduces Tmrt, while ventilation enhances convective heat loss and lowers perceived temperature. For PET, ventilated conditions consistently outperformed no-wind scenarios, with reductions of approximately 1°C and 0.7°C in shaded and sun-exposed sites, respectively. Analysis of subjective human responses indicated that under shaded conditions, when wind speed exceeded 0.3m/s, approximately 81% of participants reported thermal comfort, and overall comfort increased with higher wind speeds. In contrast, under sun-exposed conditions, even with increasing wind speeds, TCV and OCV rarely reached the comfort threshold, suggesting that high solar radiation is the dominant factor limiting the effectiveness of ventilation. Nevertheless, when wind speed ranged between 0.3 m/s to 0.9m/s, comfort levels improved for about 20% of participants. Furthermore, using the PET neutral temperature in previous studies as a reference, and accounting for warming trends and thermal adaptation associated with climate change, the subjectively adjusted results indicate that thermal tolerance increases in both shaded and sun-exposed environments.
This study demonstrates that the effectiveness of ventilation is strongly modulated by solar radiation. Under high-radiation conditions, shading should be prioritized to reduce thermal load, with ventilation serving as a complementary strategy to enhance overall comfort. The proposed PET adjustment model improves the accuracy of thermal comfort assessment in hot-humid climates, providing evidence-based guidance for urban planning and architectural design to optimize outdoor thermal environments.
How to cite: Chen, Y.-L., Matzarakis, A., and Lin, T.-P.: Effects of Shading and Ventilation Interactions on Outdoor Human Thermal Comfort, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-208, https://doi.org/10.5194/ems2026-208, 2026.
Human health is directly influenced by environmental conditions associated with temperature, relative humidity, wind and incoming solar radiation. Among these, temperature and humidity exert the greatest influence on thermal comfort and human well-being. To assess thermal stress, various bioclimatic indices have been developed to simplify the complex interactions between atmospheric variables and human perception, enabling meaningful comparisons across different climatic regions. Thom’s Discomfort Index (TDI), introduced in 1957, is the most widely accepted and the first physiological index of its kind, primarily designed to describe discomfort at the population level (e.g. what percentage of people feel stressed), has been analyzed across the globe in areas with different climatology.
Athens has undergone continuous urbanization since the 1950s, characterized by rapid expansion and increased building density. This development has intensified the urban heat island effect, contributing to local warming and altering the climatic characteristics of the Athens basin, especially during summer, which are characterized by long periods of sunshine, high temperatures and varying levels of humidity. Concurrently, the city has experienced significant regional climate change since the mid-1980s, futher amplifying thermal stress conditions.
This study investigates the temporal evolution of thermal discomfort in the historic center of Athens, using one of the oldest, largest and most homogeneous urban meteorological datasets in the Mediterranean region, recorded at the National Observatory of Athens (Thissio station). The dataset spans more than a century (1901-2024) and is available at hourly resolution, allowing for a robust assessment of both long-term trends and short-term extremes. This high temporal resolution provides a clear advantage over studies based solely on daily observations. Within the Mediterranean climatic context of Athens, TDI index is particularly suitable for evaluating long-term variability and changes in thermal stress conditions.
This comprehensive analysis reveals a clear shift toward more frequent, intense and prolonged heat stress conditions since the 1980s, with a marked acceleration after 2000. In earlier decades, high discomfort conditions were sporadic and largely confined to July and August. After 1980, however, they became more systematic and extended from June to September, occasionally reaching October. Extreme discomfort levels (TDI≥32°C), which were virtually absent before 1980, have emerged during the last two decades. Additionally, the duration of the high-risk period has increased substantially, exceeding 90 days in some recent years, compared to fewer than 40 days during the early 20th century.
These findings demonstrate how rising temperature and humidity amplify heat stress in a Mediterranean city and emphasize the need for adaptation strategies in urban planning and public health to reduce vulnerability to extreme heat.
How to cite: Psiloglou, B., Gkinis, N., and Giannakopoulos, C.: Temporal Discomfort Variation in the Eastern Mediterranean city of Athens, Greece. Part 1: Analysis of High Resolution Measurements Since the Beginning of the 20th century (1901-2024)., EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-344, https://doi.org/10.5194/ems2026-344, 2026.
Ioannina, a mid‑sized city in northwestern Greece, presents a highly heterogeneous urban landscape shaped by its long historical evolution, dense medieval core, and proximity to Lake Pamvotis. The combination of narrow alleys, enclosed courtyards, open plazas, and scattered green pockets creates a complex microclimatic mosaic that strongly influences human thermal perception. In recent years, rising summer temperatures and prolonged heat episodes have intensified the need to better understand how urban morphology and vegetation affect thermal comfort in Mediterranean historic cities.
This study investigates human thermal sensation in the historical center of Ioannina by integrating high‑resolution field measurements with detailed microclimate simulations. On August 8, 2025, air temperature, relative humidity, wind speed, and globe temperature were recorded along a pedestrian transect specifically designed to capture the city’s diverse urban typologies—from shaded, narrow alleys to open plazas and vegetated areas. Measurements were taken every 2 seconds at a height of 1.1 m, corresponding to the gravitational center of the human body, between 15:00 and 17:00 (UTC+3:00).
Thermal comfort was assessed using two established human‑energy‑balance indices, the Physiologically Equivalent Temperature (PET) and the Universal Thermal Climate Index (UTCI). These indicators enabled a detailed evaluation of how different urban morphologies and varying levels of shading and vegetation influence perceived heat stress. To complement the field campaign, microclimate simulations were performed using 3D modelling ENVI-met, at very high resolution (1.5m x 1.5m), providing spatially explicit estimates of PET, UTCI, and CO₂ concentrations under both existing conditions and alternative design scenarios.
The combined analysis proved spatial variability in thermal stress across the study area, driven primarily by differences in shading, surface materials, and vegetation density. Field observations and ENVI‑met outputs consistently indicated elevated PET and UTCI values in exposed plazas and narrow, sunlit streets, while vegetated pockets and shaded corridors exhibited noticeably lower thermal loads. Simulated CO₂ concentrations further emphasized the contribution of vegetation to improved air quality, with greener configurations demonstrating measurable reductions in near‑surface CO₂ levels. Building on these findings, the study evaluates targeted nature‑based mitigation strategies, including the installation of extensive green roofs and the development of a small urban woodland. Scenario simulations show that these interventions can substantially reduce radiant heat exposure, enhance evaporative cooling, and contribute to improved atmospheric conditions. Overall, the results underscore the potential of green infrastructure to enhance thermal comfort and environmental resilience within Ioannina’s historic urban core.
How to cite: Nastos, P. T., Polychroni, I., Nastou, M. –. P. P., and Chasiotis, A.: Microclimate, Thermal Stress, and Nature‑Based Solutions in Ioannina, Greece: An Integrated Field and Simulation Approach, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-368, https://doi.org/10.5194/ems2026-368, 2026.
Urban heat stress is an escalating concern in Mediterranean cities, which are climate-change hotspots, and is associated with increased mortality and adverse health outcomes. These risks highlight the need for evidence-based strategies to reduce thermal exposure in dense urban environments, with urban trees representing a key nature-based mitigation measure. Computational Fluid Dynamics (CFD) is widely used to study urban microclimates; however, many studies rely on idealized canyon geometries, and only a limited number incorporate thermophysiological indices to assess how urban microclimates influence human thermal perception1. This study uses a coupled CFD–SOLWEIG framework with UTCI-based assessment to enable integrated evaluation of urban microclimate and pedestrian thermal stress. High-resolution simulations were conducted and validated in a dense Mediterranean urban fabric in the historical centre of Nicosia (Cyprus) using ANSYS Fluent. Unsteady Reynolds-Averaged Navier–Stokes simulations were performed over a 24-hour summer period using detailed urban geometry to resolve airflow and air temperature, while mean radiant temperature was calculated using the SOLWEIG2 radiative model. These variables were combined in the UTCI-Fiala model to estimate UTCI at pedestrian level3. Urban trees were represented as porous canopy volumes to account for aerodynamic drag, shading, and evapotranspirational cooling effects and to quantify their mitigation role. Simulation results were validated using field observations, yielding mean absolute deviations of 1.48°C for air temperature (R²=0.89) and 0.68m s⁻¹ for wind speed (R²=0.67). UTCI exhibits a pronounced diurnal cycle driven by solar radiation, increasing from below 30°C in the early morning to above 45°C around midday. Even isolated urban trees can locally mitigate thermal stress by reducing radiative loading and air temperature through shading and evapotranspiration. UTCI reductions reach up to 5.1°C during peak solar hours at pedestrian level beneath the tree canopy, while evapotranspiration alone contributes reductions of up to 2.4°C under shaded conditions. Vegetation also generates localized cooling zones extending downstream up to three times the tree crown width, depending on local wind conditions. These results highlight the capacity of urban trees to significantly reduce pedestrian thermal stress and demonstrate the potential of the CFD–SOLWEIG–UTCI framework to support climate-responsive urban planning in dense built environments, providing quantitative evidence to inform heat mitigation strategies and urban design.
1. Antoniou, N., Montazeri, H., Blocken, B. & Neophytou, M. K. A. On the impact of climate change on urban microclimate, thermal comfort, and human health: multiscale numerical simulations. Build. Environ. (2024).
2. Lindberg, F., Holmer, B. & Thorsson, S. SOLWEIG 1.0 – Modelling spatial variations of 3D radiant fluxes and mean radiant temperature in complex urban settings. Int J Biometeorol 52, 697–713 (2008).
3. Fiala, D., Havenith, G., Bröde, P., Kampmann, B. & Jendritzky, G. UTCI-Fiala multi-node model of human heat transfer and temperature regulation. Int J Biometeorol 56, 429–441 (2012)
How to cite: Alexandrou, G., Antoniou, N., Mouzourides, P., and Neophytou, M.: Quantifying the Cooling Effects of Urban Trees on Pedestrian Heat Stress in a Dense Mediterranean Urban Environment, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-509, https://doi.org/10.5194/ems2026-509, 2026.
In response to the intensifying Urban Heat Island (UHI) effect, enhancing urban ventilation has become a key strategy for mitigating elevated temperatures. Urban microclimates are strongly influenced by building height and spacing, which can induce substantial changes in local wind environments. However, most previous studies focus on ground-level ventilation, with limited systematic investigation of mid-to-low elevation zones (6–24 m).
This study combines field measurements at three social housing sites in Taipei City with Computational Fluid Dynamics (CFD) simulations to quantify ventilation rates and identify key design parameters. Standardized building models with three heights (25 m, 46 m, 61 m) and five spacing intervals （3 m、6 m、12 m、15 m、18 m） were analyzed to evaluate airflow variations across multiple vertical sections. Observational data from the Central Weather Administration (CWA) were used to define background wind and boundary conditions.
Results indicate significant interactions between building height and spacing in shaping vertical wind speed. Wind speed at 2 m above ground increases with building height due to downwash effects, but at 24 m height, wind speed decreases as height increases and spacing narrows. Wider spacing enhances ventilation coverage: at 25 m, it expands zones with wind speed ≥ 2.5 m/s, while at 46 m it improves basic zones with wind speed ≥ 0.5 m/s. High-rise, narrow-spacing configurations suppress mid-to-upper-level airflow, reducing overall ventilation rates.
CFD simulations using Flow Designer achieved an R² of up to 0.96 between building spacing and ventilation rate, indicating strong correlation. Future work will employ Large Eddy Simulation (LES) to capture transient wind field dynamics and integrate vegetation-based environmental adaptation strategies. These findings provide practical guidance for social housing and urban planning in dense urban areas, enhancing microclimate comfort and building energy efficiency.
How to cite: Lin, T.-P., Wu, P.-E., Yang, Z.-Y., and Chen, Y.-L.: Integrating Field Measurements and Simulation Analysis to Evaluate the Influence of Urban Building Configuration on Near-Surface Wind Fields, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-370, https://doi.org/10.5194/ems2026-370, 2026.
Thermal exposure risks in high-density urban environments directly impact pedestrian health. In the precincts surrounding Taipei 101, super-tall buildings induce complex street-level vortices that significantly attenuate near-ground wind speeds. This study investigates the coupling effects between anthropogenic heat emissions from air conditioning systems (AC) and urban street flow fields. AC exhaust heat is frequently trapped at the pedestrian level (1.5 m) by micro-scale vortices, and improper configurations lead to a pronounced Thermal Retention Effect.
To establish a data-driven evaluation framework and translate simulation outputs into actionable building heat-discharge strategies, this research employs Large Eddy Simulation (LES) to conduct transient thermo-fluid flow-field modeling, validated through on-site measurements. For the 1.5 m near-ground micro-environment, Physiological Equivalent Temperature (PET) is adopted as the thermal stress index, integrating air temperature (Ta), wind speed (V), and mean radiant temperature (Tmrt).
Recognizing that conventional CFD approaches struggle to provide quantitative weighting of heat-accumulation factors and to identify dominant thermal mechanisms, this study introduces a Machine Learning (ML) model to quantify the relative contributions of different AC installation positions to localized heat accumulation, thereby establishing an efficient and predictive thermal-load assessment framework.
Results indicate that leeward vortices in dense residential districts produce a heat-retention rate of 60%, driving pedestrian-level PET into the Extreme Heat Stress category. ML feature-importance analysis reveals that the interaction between discharge positioning and vortex circulation is the dominant thermal driver. Optimization of AC configurations reduces the spatial extent of high heat-accumulation zones from 60% to 25%, significantly mitigating thermal vulnerability and localized heat hazards caused by Thermal Trapping.
This study confirms that the coupling between street vortices and anthropogenic heat emissions is the primary physical driver of near-ground microclimate deterioration. By optimizing AC placement (windward, leeward, crosswind, or rooftop) via the ML model, localized heat loads within the urban canyon can be effectively removed through ventilation-enhanced heat dissipation, enabling a functional decoupling between building heat discharge and ambient flow fields.
Keywords: Human Biometeorology; Urban Canyon; LES; Machine Learning; Physiological Equivalent Temperature (PET); Anthropogenic Heat; AC Configuration Optimization
How to cite: Zi-Yi, Y., Shiang-Yu, W., Kuo-An, H., Matzarakis, A., and Tzu-Ping, L.: LES-Based Optimization of Urban Thermal Comfort Using Machine Learning, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-234, https://doi.org/10.5194/ems2026-234, 2026.
With the intensification of climate change, the frequency and severity of extreme heat events are increasing, posing significantly elevated heat-related risks to outdoor workers. This study adopts the Heat Index (HI), a commonly used indicator for assessing heat risk among construction workers, and integrates future climate projections derived from AR6 TaiESM1-WRF, which is one of the latest dynamically downscaled climate products developed in Taiwan (Lee, W.-L et al., 2020), to evaluate the effectiveness of two long-term adaptation strategies: work schedule adjustment and prefabrication methods.
For work schedule adjustment, strategies such as starting work earlier, extending midday breaks, delaying finishing times, and implementing nighttime construction are considered to reduce exposure to high-temperature conditions. July is selected as a representative month to calculate the number of hours during which the Heat Index exceeds Level 3 (which is considered equivalent to Level 4 under solar exposure according to Taiwan’s occupational safety regulations). The analysis further compares the variations in heat exposure under baseline, +2°C, and +3°C global warming scenarios across different work schedule arrangements.
Regarding prefabrication, construction tasks traditionally performed outdoors—such as concrete pouring, rebar tying, and mechanical and electrical installations—are relocated to indoor factory settings. This transition effectively reduces the duration of outdoor work under high-temperature conditions. Using a standard work schedule (08:00–17:00, including a one-hour lunch break), this study calculates the monthly hours exceeding the heat threshold throughout the year and estimates the reduction in heat exposure risk when outdoor construction periods are shortened by one month.
The results indicate that work schedule adjustments can effectively avoid peak heat exposure periods, while prefabrication reduces outdoor exposure at the source. Both strategies demonstrate significant cooling adaptation benefits. The findings provide valuable insights for improving occupational safety regulations and informing future climate adaptation policies.
How to cite: Liu-Chen, W. and Tzu-Ping, L.: Evaluating Cooling Adaptation Benefits for Outdoor Workers under Climate Change-Induced Extreme Heat, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-272, https://doi.org/10.5194/ems2026-272, 2026.
The UTCI index determines the impact of weather on human by combining four meteorological variables, that is, temperature, wind speed, humidity, and mean radiant temperature. In this contribution, the causes of fast changes in the UTCI index in the Czech Republic are assessed. We utilized the Aladin Reanalysis, which covers large area of Europe. The reanalysis has two advantages. Firstly, the 2.3 km resolution provides great detail on topography, and secondly, the UTCI is computed in the post-processing stage at hourly intervals. Hence, there is a possibility to examine the changes in the index in a subdaily time step. We calculated changes in the index in 12-hour intervals in the period 1991-2020 for separate seasons. The largest changes, reaching up to 30 °C, are detected in winter and spring, while smaller values being found particularly in summer. We find out that the passing of fronts accounts for a substantial portion of large changes in the UTCI index. For instance, cold fronts, responsible for the inversion disruption, may lead to a substantial increase in UTCI during the night in winter. Yet, in other cases, cold fronts accompanied by stronger winds may also lead to a substantial decrease in UTCI. Fast changes in UTCI in summer are always connected with fronts; we observe that increase (decrease) in UTCI is linked with warm (cold) fronts. Anticyclonic conditions take part in increase in UTCI on morning and before noon, particularly in cold months. In such situations, we observe that the growing MRT reflects in rise in UTCI. This work contributes to operational meteorology by describing the impact of subdaily weather changes on humans.
How to cite: Hynčica, M., Grznár, D., Novák, M., Došková, L., and Hrubý, J.: Attribution of fast changes in UTCI to synoptic systems , EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-277, https://doi.org/10.5194/ems2026-277, 2026.
Influenza is an acute respiratory infection that causes recurring seasonal epidemics and is associated with substantial morbidity and mortality. In temperate climates, the influenza season usually peaks in winter; however, the timing and severity of epidemics vary considerably from year to year. Previous research has shown that this variability relates to meteorological factors such as air temperature and absolute humidity. It remains uncertain whether synoptic circulation types can serve as a useful parameter for evaluating the impact of weather on the timing and dynamics of influenza epidemics.
The Grosswetterlagen reanalysis classification of daily synoptic circulation types over Central Europe is used to characterise winter weather (December–March) in the Czech Republic from 1982 to 2020. The average frequency of synoptic types is calculated over two-week periods aligned with the start, peak, and end of epidemics. These are categorised by their effects on excess mortality (mild, moderate, or severe) and by the dominant influenza virus (A/H3N2, A/H1N1, or B). The relationship between synoptic types and influenza epidemics over time is analysed through bootstrapping. Excess mortality during epidemics is estimated using a quasi-Poisson regression model.
Results show that the onset of influenza epidemics is typically preceded by a higher frequency of westerly types, which is compensated by fewer easterly types. During epidemics, this pattern shifts when westerly types are strongly suppressed, allowing easterly (namely north-easterly and south-easterly) types to predominate and bring cold, continental air into the region. In non-epidemic seasons, the opposite pattern is observed, with predominating westerly types and milder, humid winter conditions. Severe epidemics with high mortality impacts are associated with frequent anticyclonic situations, prevailing north-easterly and south-easterly types, and suppressed westerly and north-westerly types, corresponding to cold, dry winter conditions with frequent temperature inversions. The weather patterns accompanying A/H3N2 and A/H1N1 epidemics differ: A/H3N2 is associated with anticyclonic conditions, with frequent south-easterly types and high pressure over central Europe, while westerly types are suppressed, representing a stable, colder-than-average, and dry winter regime. During A/H1N1 epidemics, the occurrence of westerly types is at the seasonal average, while south-westerly types are more frequent, indicating more variable weather, including milder temperatures and more frequent precipitation. Influenza B epidemics are associated with a higher frequency of easterly and northerly types and a lower frequency of westerly and southerly types, reflecting stable, dry continental conditions with below-average temperatures.
Synoptic circulation represents a complex indicator of meteorological conditions that influence the timing and severity of influenza epidemics and provides an integrated view of the effects of individual meteorological variables, which may contribute to improved seasonal risk assessment.
How to cite: Hanzlíková, H., Plavcová, E., Kyselý, J., and Urban, A.: Winter synoptic circulation types and influenza epidemics in the Czech Republic, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-321, https://doi.org/10.5194/ems2026-321, 2026.
Heat has emerged as a major public health concern. Over 62,000 heat-related deaths were estimated to have occurred during the European summer of 2024, exemplifying the pressing need to develop effective early warning systems. Such systems depend critically on the quality of the underlying forecasts, and recent work has focused on developing impact-based forecasts for heat-related mortality, which provide impact-oriented information. To date, heat-related mortality forecasts have been based on the output of numerical weather prediction models, or physics-based forecasts. The field of weather forecasting is undergoing a rapid transformation with the advent of skillful data-driven forecasts. This study compares European temperature-related mortality forecasts for summer 2024 based on physics-based weather forecasts with those based on data-driven weather forecasts. Our results highlight that both the physics-based and data-driven forecasts systematically underestimate temperature-related mortality, more pronouncedly so in the latter. Both types of forecasts appear sensitive to forecast errors at hot temperatures, due to the non-linear relationship between temperature and mortality. Nevertheless, temperature-related mortality forecasts based on data-driven weather forecasts appear to be a promising alternative to traditional physics-based weather forecasts, and targeted improvement of the representation of hot temperatures through bias correction or adjustment of the loss function to give greater weighting to hot temperatures would be beneficial for temperature-related mortality forecasting. This represents an important step for the verifications of the capacity for data-driven forecasts to inform decision makers about societal impacts. We suggest the application of this approach to both data-driven and physics-based forecast ensembles as an important next step in the continued development of informative, impact-oriented forecasts.
How to cite: Holmberg, E. and Olivetti, L.: Forecasting European temperature-related mortality in Summer 2024: data-driven vs physics-based forecast approaches, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-128, https://doi.org/10.5194/ems2026-128, 2026.
Around 2.5-3 million European citizens, including over 100,000 in Poland, are affected by a complex chronic inflammatory bowel disease (IBD). The number of IBD-related illnesses and deaths is still increasing, while highlighting inequalities in developing countries. As a complex disruption in everyday life and far-reaching social consequences, with no clear address to triggers, IBD flares pose a serious challenge to the public health sector.
The aim of the study was to investigate variability in emergency hospitalisations among patients with noninfectious IBD at the population level in Poland and to identify the risk levels associated with atmospheric conditions. The analysis covered an 8-year period (1 January 2012 - 31 December 2019), where a total of 66,657 urgent IBD hospitalisations, including diagnoses of Crohn’s Disease (ICD-10: K50) – 24,778 and Ulcerative Colitis (ICD-10: K51)- 41,879, were studied. A targeted time-stratified case-crossover analysis was conducted to evaluate short-term associations between ambient PM10, PM2.5, SO2, O3, and NOX and meteorological factors like air temperature, atmospheric pressure, air vapour pressure, and solar radiation, and urgent hospital admissions for inflammatory bowel disease (IBD). The clearest signal was observed for the same day or with a one-day lag after increased NOx exposure, enhanced by the effect of higher solar radiation totals (lag 4) in the working-age group 19-60 years old, and particularly evident in urban areas. The signs were evident in both groups, though more pronounced in UC patients. Changing living environment and daily habits may require greater effort, sacrifice, and costs than optimised self-care, including mitigating unfavourable conditions that contribute to exacerbation. In this context, results from biometeorological studies may provide significant support to the healthcare sector.
How to cite: Wieczorek, J., Bochenek, B., Goryński, P., and Jankowski, M.: Air pollution and meteorological drivers of the risk of urgent IBD hospital admission in Poland, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-318, https://doi.org/10.5194/ems2026-318, 2026.
Poland has remained one of the most polluted countries in the EU for years. In 2021, the health costs of exposure to elevated concentrations of fine particulate matter in the air were estimated at 47,300 attributable deaths and 519,000 years of life lost for Polish citizens. Analysis is based on the first and comprehensive nationwide, long-term study for Poland (2012-2019), integrated daily datasets of air pollution and meteorological measurements from institutional WMO and Environmental Protection networks, and detailed registers of emergency hospital admissions due to COPD from the National Institute of Public Health. Surface analysis using TERYT codes enabled the assessment of variability in moving averages of atmospheric and environmental factors and of urgent hospitalization, as well as the identification of additional patient characteristics that affect the individual risk of short-term exposure leading to hospitalization.
Our distributed lag non-linear models (DLNM) indicated robust short-term associations between ambient air pollution and meteorological conditions and urgent COPD admissions. Main finding: consistent with our previous results, sulfur dioxide (SO2) levels provide the strongest predictive signal for variations in COPD hospitalizations in Poland. Across the study period, higher SO2 levels were consistently associated with increased cumulative hospitalization risk, observed in both sexes, with slightly stronger cumulative estimates in men. While warmer conditions, as reflected in higher daily minimum and maximum temperatures, significantly reduced the risk of urgent hospitalization for COPD. Air temperature associations were observed in both sexes; however, the magnitude varied by indicator. Results for PM10, PM2.5, and NOx were slightly weaker and less consistent, e.g., NOx associations were more apparent in men and less consistent in women. After accounting for lagged effects, this suggests that not all pollutant signals are equally stable (partially seasonally drifted) at the nationwide level.
Short-term environmental impacts observed on COPD hospitalizations are not acute - lag-response plots in all pollutants were several days, rather than limited to the exposure day. For gaseous pollutants, the lag structure suggested delayed cumulative impacts. For air temperature, risk reductions typically emerged after short delays, reached a peak on lag 14 days, and then attenuated toward later lags. Overall, our findings support the use of distributed lag frameworks in nationwide COPD burden assessments and emphasize the need to implement subgroup-specific prevention strategies.
How to cite: Bochenek, B., Wieczorek, J., Goryński, P., and Jankowski, M.: Air pollution and meteorological factors affecting emergency hospital admissions of 630,059 respiratory patients in Poland , EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-319, https://doi.org/10.5194/ems2026-319, 2026.
High temperature extremes significantly threaten public health, prompting many countries to implement heat early warning systems (HEWSs). Many European countries adopted a HEWS after the 2003 heatwave, taking into account specific regional needs and country-specific characteristics. While some smaller countries issue country-wide alerts, others deploy regional or city-specific warnings. Moreover, certain countries have alert criteria tailored individually for different regions, reflecting local climatic conditions, urban heat island effects, and variations in population vulnerability.
The existing research mostly focuses on the HEWS or Heat-Health Action Plans (HHAPs) as a whole. So far, a limited number of studies has analysed the actual data of issued heat alerts – out of these studies, virtually all focus on a single country. We collected records of heat alerts issued in the past from 16 European countries to thoroughly investigate the utility of European HEWS, and we present an inter-country comparison highlighting the unique characteristics of the applied HEWSs. The countries included in our study are Belgium, Cyprus, Denmark, Finland, France, Germany, Hungary, Ireland, Netherlands, Poland, Portugal, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
Our objective is to introduce the data in a novel way by incorporating ERA5-Land reanalysis data to characterize the meteorological conditions on days when heat alerts were issued, and to assess their consistency. The aim is to provide insights into the correlations between heat warnings and actual weather patterns, thereby enhancing our understanding of how these systems can be optimized for better public health outcomes.
This study serves as a foundational step for a broader, more detailed analysis aimed at evaluating the effectiveness of heat alerts in protecting public health. Future research will adopt a counterfactual approach, comparing observed outcomes such as mortality on heat alert days with outcomes on climatically comparable days that could be eligible for the same heat warning, thus providing a clearer picture of the impact and efficiency of HEWSs.
How to cite: Kořistková, M., Urban, A., and Huber, V.: Mapping heat alert systems across Europe, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-693, https://doi.org/10.5194/ems2026-693, 2026.
The 2003 European heatwave caused unprecedented fatalities, highlighting society’s vulnerability to extreme thermal events. Recent summers in the Basque Country (2023, 2025) have seen a recurrence of intense heatwaves, including rising water temperatures and a direct impact on beach management and coastal operations, necessitating urgent assessment of their impact on the coastal maritime sector, an area often overlooked in occupational biometeorology. This study’s main objective is the identification of short- and long-term impacts, such as impacts on operational sites (ports, docks and cargo ships) and impacts on human health, respectively. We analyzed hourly meteorological data from several coastal stations in the Basque Country during the summer heatwaves of 2003, 2023, and 2025 (specifically August in this last summer). Air temperature and relative humidity were used to calculate the Heat Index (HI) according to the NWS scale, assuming moderate physical work under protective clothing and direct solar exposure, conditions typical for deck crews and stevedores. During the August heatwave in 2025 (13th of August-18th of August), the HI reached extreme temperature values for several hours in a row in parts of Bilbao, exceeding the occupational safety threshold. Heatwave days increased the frequency of extreme thermal stress hours compared to a normal summer baseline. Crucially, the end of heat-related high-pressure systems triggered a considerable increase in wave height variability and wind gusts within 24 hours, directly elevating the risk of maritime incidents (slips, falls, crane operations) during port operations and coastal navigation. Besides the direct impact, heatwaves pose a dual threat: acute and chronic occupational health risks (heat stroke, dehydration, cardiovascular strain, etc.) for maritime workers, and increased operational instability due to rapid ocean-weather variability immediately after the end of a heatwave. We propose integrating biometeorological thresholds into national and port-specific early warning systems for maritime safety, as well as raising awareness about labour health, informing relevant authorities that certain jobs or individuals may be particularly vulnerable to heatwaves and related episodes. Meteorological warning/alert/alarm systems could be adapted to coastal labour, evaluating impacts on the sector, and decreasing or avoiding incidents.
How to cite: Zabala, I., Maruri, M. D. L. M., Basterrechea, I., Sotes, I., and Sanchez-Beaskoetxea, F. J.: The impact of heatwaves on human health and the maritime sector, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-730, https://doi.org/10.5194/ems2026-730, 2026.
The first version of the biometeorological module (BIO) in PALM was published in 2020. The module contained three widely used and well-validated indices: i) perceived temperature (PT), ii) universal thermal climate index (UTCI), and iii) physiologically equivalent temperature (PET). Supported indices were calculated directly in PALM and used as user-defined outputs. However, the current implementation had several important limitations. The most critical shortcoming was the necessity to re-run the entire simulation whenever the user changed any hardcoded parameters of the indices. Other limitations included unclear parameterisations of the mean radiant temperature (MRT) reference shape, missing documentation for some indices (primarily PET), and problematic parallelisation or temporal averaging. Those limitations often resulted in inconsistent outputs. To solve these issues, we developed a new version of the BIO module, PALM-BIO 2.0. Most essential updates are as follows: clean code structure following internal code standards, adoption of a unified naming convention, various parameterisations for MRT calculation (e.g., black-globe thermometer, ellipsoidal approximation of the human body), preparation of the indices for the physiological module updates, and index corrections and improvements following current research (especially PET). To eliminate the need to re-run PALM simulations when only biometeorological input parameters change, the code was extended to output the meteorological variables required to calculate biometeorological indices into an intermediate file, enabling their calculation in a postprocessing stage. A postprocessing utility was also developed as a part of this update. PALM-BIO 2.0 is prepared for easy extension; for example, two new indices are being implemented: wet-bulb globe temperature (WBGT) and humidity index (HUMIDEX). Finally, our plans also consider UTCI*, adjusted UTCI, and the Dynamic Mean thermal sensation Vote (DMV).
How to cite: Geletic, J., Belda, M., Krč, P., Matonoha, C., and Resler, J.: PALM-BIO 2.0: Introducing the modernised biometeorology module, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-563, https://doi.org/10.5194/ems2026-563, 2026.
Outdoor thermal comfort is one of the key factors affecting human well-being and health in urban environments. Despite threatening billions worldwide, urban heat remains difficult to mitigate effectively. Cities struggle to pinpoint intervention priorities at the pedestrian scale where thermal stress is most acutely experienced. Furthermore, how people perceive and cope with heat extends far beyond thermal exposure; psychological and behavioural responses play a crucial yet often overlooked role. Meanwhile, the variables driving thermal stress remain highly variable at the microscale, falling well below the resolution of conventional monitoring networks and weather-based warning systems. This study presents an integrated approach coupling high-fidelity PALM simulations (1-metre/1-minute resolution) with thermal walks (n = 3,666 georeferenced thermal sensation votes, TSV), applied to Prague-Holešovice (Czech Republic) on a hot summer day. By directly linking human thermal perception with modelling outputs, we assess which variables best explain what people actually experience outdoors and whether a model can reflect human thermal sensation. Our results identify modelled Mean Radiant Temperature (MRT) as the dominant predictor of TSV, exhibiting the highest spatiotemporal variability across the study area, with UTCI showing a similarly significant relationship owing to its strong dependence on MRT. In contrast, air temperature showed minimal spatial variation (≤ 0.3 °C within streets) and substantially lower predictive power, with direct implications for urban warning systems that continue to rely predominantly on air temperature. Distinct spatial patterns were evident at street level. The northern sides of east–west-oriented unshaded streets were systematic thermal hotspots. Mature street trees reduced reported severe thermal discomfort by more than half. Open impervious surfaces amplified heat stress to levels matching the worst street conditions, yet accessible green spaces just tens of metres away offered substantial thermal refuges. The findings highlight radiation exposure as the priority target for urban heat adaptation, with microscale precision as the standard for directing interventions. This approach enables cities to communicate heat risk effectively and act where it matters most.
How to cite: Geletic, J., Kvetonova, V., Brabec, M., Lehnert, M., Bures, M., Sipek, V., Crank, P. J., and Resler, J.: How well can a model capture human thermal sensation? Bridging high-resolution simulations with thermal walks, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-678, https://doi.org/10.5194/ems2026-678, 2026.
The RayMan model was created to evaluate short wave (SW) and long wave (LW) radiation fluxes which carry significant impacts upon the humans. The model provides a means to evaluate building structures of diverse complexities which allows it to analyse the effect of numerous planning and design scenarios at multiple scales. The model calculates mean radiant temperature (Tmrt) a variable that is crucial within the human energy balance model, thus permitting the evaluation of microclimatic factors upon the human biometeorological system. In correlation with the previously mentioned thermal indices, the PMV, PET, SET*, UTCI, PT, and mPET, can be calculated within the RayMan model. Furthermore, specificities pertaining to urban typo-morphological characteristics and amenities can be created and/or imported within its embedded obstacle plug-in. Such an input task, if required, can moreover be aided through the superimposition over a respective raster file to specify the position of such elements, as well as the importation of shape and/or text files to introduce obstacles and/or topographical characteristics.
Consequently, and based upon these described input possibilities, sunshine duration (accounting, or not, for the ratio of sky restriction, via the Sky View Factor (SVF)), assessment of diurnal and/or nocturnal mean, max or total of G for present and future urban settings can be examined. In association with the estimation of thermal indices within complex environments, the user can introduce meteorological data manually, or do so via the importing of different data files (based upon divergent periodicities, resolutions, and time-frames), which must be selected appropriately based upon the intended nature of the desired study and/or statistical assessments.
In addition, the model outputs of MEMI and mPET-Model can be calculated for additional or epidemiological studies. Furthermore, the in stationary approach can be performed for additional time- and spatial analysis in the micro scale for indoor and outdoor climates.
Several applications such as micro scale modifications in urban areas, setting up thresholds for heat health warnings and for extreme events (i.e. FIFA 2022 and Olympic Games in Tokyo) have been helpful for decision making and communication.
How to cite: Matzarakis, A.: RayMan and Thermal Bioclimate – History, Development, Applications and Additional Features, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-756, https://doi.org/10.5194/ems2026-756, 2026.
Extreme weather conditions and climate‑related events increasingly shape daily life and the functioning of essential infrastructure. Human societies and built environments are vulnerable to a broad spectrum of environmental hazards, including forest fires, drought, rising sea levels, extreme precipitation and prolonged extreme heat and heat waves. Among these hazards, extreme heat poses one of the most immediate and pervasive risks, particularly in densely populated urban areas where people are exposed to intensified thermal stress. This exposure is expected to increase further in the coming decades as climate change progresses and urbanisation continues.
Communicating effectively about heat therefore requires a comprehensive and multifaceted approach. It must address short‑term exposure during both daytime and nighttime, highlight the importance of cool shelters, and promote the creation and maintenance of urban areas with naturally lower thermal loads, such as parks, shaded streets, water features and green spaces. These environments not only reduce heat exposure but also support physical and mental well‑being during extreme weather events.
Clear and targeted communication is essential to ensure that information, warnings and explanations reach the media, decision‑makers and the public in an appropriate and timely manner. Different target groups—such as vulnerable populations, health professionals, city planners or journalists—have distinct needs, expectations and decision‑making contexts. Communication strategies must therefore be tailored, easy to understand and enriched with practical solutions, behavioural recommendations and examples of effective adaptation measures. In addition to formal heat‑health warnings, messages should be framed in accessible language and supported by visual tools that help translate complex climate‑health relationships into actionable guidance.
A series of examples will be presented and analysed, using heat as a central case to illustrate key principles of effective communication. These insights draw on recent experiences with public and media communication across Europe and highlight the growing importance of clear, science‑based messaging in a warming world.
How to cite: Matzarakis, A.: Communicating Extreme Heat and Health, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-757, https://doi.org/10.5194/ems2026-757, 2026.
In 2026, the Czech Republic completed a comprehensive reform of its national Impact‑Based Warning System (IWSS), driven by new legislation including the Act on the Public Hydrometeorological Service and its implementing decree issued by the Ministry of the Environment. A key innovation is the introduction of two new warning categories—Heat Stress and Cold Stress—which together form an embedded early warning subsystem targeting expected human thermal discomfort. This marks the first official establishment of a national Heat Health Warning System in the Czech Republic.
The core of this system is the assessment of anticipated thermal stress using the Universal Thermal Climate Index (UTCI), specifically its forecasted daily extreme values as well as daily means. The system therefore evaluates not only the peak stress represented by the relevant extreme (UTCImax for heat stress and UTCImin for cold stress), but also the duration of stressful conditions without sufficiently long recovery intervals for the human organism. Combining both perspectives enables the detection of expected heat waves and cold spells characterized by several consecutive days of elevated physiological burden.
The Czech Hydrometeorological Institute (CHMI) adopted this approach following the recent availability of UTCI outputs from numerical weather prediction models and the development of a UTCI climatology for the Czech Republic for 1991–2020 within the PERUN project, which provided an objective basis for defining warning criteria.
These warning products are intended primarily for the Integrated Rescue System of the Czech Republic, but also for national authorities (notably the Ministries of Health and Labour and Social Affairs) and regional and municipal administrations. With the operational launch of the system on 1 July 2026, the state now has a clearly defined, unified foundation for the long‑delayed development of a national Heat Health Action Plan, as well as for subsequent regional and municipal action plans, particularly in larger urban areas.
Acknowledgement: This research was founded by Technology Agency of the Czech Republic, grant number SS02030040, project name „Prediction, Evaluation and Research for Understanding National sensitivity and impacts of drought and climate change for Czechia“.
How to cite: Novak, M., Došková, L., Hrubý, J., and Hynčica, M.: The Heat Health Warning Systemi in the Czech Republic, EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-545, https://doi.org/10.5194/ems2026-545, 2026.
Human health is directly influenced by environmental conditions associated with temperature, relative humidity, wind and incoming solar radiation. Among these, temperature and humidity exert the greatest influence on thermal comfort and human well-being. To assess thermal stress, various bioclimatic indices have been developed to simplify the complex interactions between atmospheric variables and human perception, enabling meaningful comparisons across different climatic regions. Thom’s Discomfort Index (TDI), introduced in 1957, is the most widely accepted and the first physiological index of its kind, primarily designed to describe discomfort at the population level, has been analyzed across the globe in areas with different climatology.
The city of Athens has undergone a continuous urbanization process that started in the 1950s, with the construction of new high-rise buildings, leading to the subsequent appearance of the urban heat island phenomenon, which contributed to Athens basin's local heating and modification of its climatic characteristics, especially during summers. Concurrently, Athens has experienced intense regional climate change in recent decades (since the mid-1980s).
The aim of the present study is to explore the temporal evolution of thermal sensation and discomfort at the historic center of Athens, incorporating air temperature (T) and relative humidity (RH) climate model projections, on 3-hour time step, for two future periods: the near (2031–2060) and the distant (2071–2100) one. Thermal discomfort is assessed using TDI index, which combines temperature and relative humidity into a single metric. TDI values were calculated from 3-hourly outputs of four EURO-CORDEX regional climate models under the RCP4.5 (intermediate) and RCP8.5 (high-emission) scenarios (IPCC AR5). Model data were bias-corrected against observations form the National Observatory of Athens (Thissio station), one of the longest and most homogeneous urban meteorological records in the Mediterranean region. The correction was performed over a reference period (1976-2005) and subsequently applied to future projections.
The results reveal a pronounced increase in the frequency and duration of high thermal discomfort conditions in the city center. Under the RCP4.5 scenario, the number of intense discomfort days is projected to increase by 21-39 days by mid-century and by approximately 1-2 months by the end of the century. Under the RCP8.5 scenario, the increase is substantially larger and becomes dramatic, with intense discomfort conditions potentially extending by up to 3 additional months annually. The contrast between the two scenarios highlights the critical role of emission mitigation in limiting future heat stress.
The study of TDI shows that climate change does not merely raise temperatures, but drastically increases perceived discomfort and heat related risk, transforming long parts of the year into thermally uncomfortable periods, highlighting the need for urgent adaptation measures in urban planning and public health to reduce vulnerability to extreme heat.
How to cite: Psiloglou, B., Gkinis, N., Machaira, P., and Giannakopoulos, C.: Temporal Discomfort Variation in the Eastern Mediterranean City of Athens, Greece. Part 2: Climate Model Predictions for Near and Distant Future., EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-365, https://doi.org/10.5194/ems2026-365, 2026.
The Jakarta Metropolitan Area (JMA) of Indonesia officially becomes the most populated urban area with 40M inhabitants. Despite its limited diurnal temperature variability, JMA is currently confronted with an exacerbation of climate change and the urban heat island (UHI) that affects health of the urban communities. Nonetheless, the number of studies on the health implications of heat exposure within this tropical environment remain limited. Prior significant research has successfully incorporated both Indonesian National Health Insurance (BPJS) and meteorological observation datasets. However, these studies have exclusively relied upon observed daily mean air temperature as the thermal proxy. Consequently, the cumulative exposure arising from the diurnal variation associated with UHI effects is potentially underestimated.
This study aims to analyze and quantify the influence of heat-stress on CVD morbidity across the thirteen districts within JMA. Consequently, this study utilizes a five-year dataset (2020-2024) incorporating hourly meteorological parameters sourced from nine stations, thereby reflecting the diurnal variation of atmospheric dynamics in the analysis. Furthermore, rather than employing the 2-m air temperature, Physiological Equivalent Temperature (PET) is examined as offering a reliable indicator for human thermoregulation. The analysis concentrates on the correlation between heat stress and the morbidity of cardiovascular disease (CVD) within primary healthcare facilities.
Preliminary findings indicate that the UHI effect influences healthcare visits for CVD in urban areas. Cumulative exposure to extreme daytime heat stress environments, as quantified by PET values in urban areas, substantially increases the incidence of CVD admissions. Conversely, the daily maximum air temperature proves to be a more suitable indicator for rural areas. These results emphasize the necessity of integrating appropriate meteorological indicators to effectively address and mitigate heat-related health risks for urban populations.
How to cite: Subasita, N., Septiono, W., Milošević, D., and Steeneveld, G.-J.: Extreme Heat Stress and Cardiovascular Diseases in the Tropical Megacity of Jakarta (Indonesia), EMS Annual Meeting 2026, Utrecht, Netherlands, 6–11 Sep 2026, EMS2026-726, https://doi.org/10.5194/ems2026-726, 2026.
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