Adaptive responses to extreme heat involve conscious (behavioral) and unconscious (physiological) efforts to mitigate exposure, yet existing research often underrepresents vulnerable populations, such as older adults, and neglects adaptation measures. This study assessed intra- and inter-individual variations in personal heat exposure (PHE), thermal perception, and physiological responses among 39 individuals aged 45–74 from diverse socio-economic backgrounds and housing types (single-unit, multi-unit, and manufactured homes) in the Phoenix Metropolitan Area, Arizona.

Using HeatSuite™ system and Kestrel Drops, we monitored indoor (living room, bedroom) and outdoor PHE alongside health indicators (heart rate, blood pressure) and self-reported thermal perceptions during 21-day periods in the summer of 2024. Results reveal significant heterogeneity in indoor temperatures, driven by adaptive capacity and thermal preferences. Over 53% of the participants slept in temperatures exceeding optimal sleep conditions, potentially affecting their well-being. Manufactured homes were not always the hottest—single-unit homes with window units often exceeded comfortable thresholds. To translate PHE into a meaningful heat stress metric, we used a liveability metric to represent the highest activity intensity a person can do safely in their thermal environment. We estimate the impact of adaptive behaviors mitigating exposure by comparing liveability values from PHE in contrast to regional weather, with personal heat exposure supporting 1.84 ± 0.99 METs higher liveability compared to airport weather data. However, liveability gains varied significantly, with a 4.29 MET gap between the highest and lowest participants, suggesting socioeconomic disparities may outweigh housing type in shaping heat resilience. Ongoing multivariate analysis explores which adaptive capacities most strongly predict liveability differences, while thermal perception and physiological responses— such as thirst prevalence, blood pressure, and heart rate—are analyzed to assess whether similar factors influence thermal comfort and physiological stress. These findings enhance understanding of individualized heat resilience, providing insights into targeted adaptation strategies beyond environmental modifications.

How to cite: Guzman-Echavarria, G., Middel, A., Ravanelli, N., Rosales Chavez, J.-B., Metzler, C., Kendra, R., Mary, M., Melissa, G., and Jennifer, V.: Decoding the Individual Adaptive Response: Insights from Summertime Personal Heat Exposure, Thermal Perception, and Heat Response in Older Adults in Phoenix, Arizona, 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-976, https://doi.org/10.5194/icuc12-976, 2025.

Most outdoor public spaces are underutilized during extremely hot weather. In the absence of adequate shading, these areas become high-risk zones, posing significant health risks, particularly for vulnerable populations such as the elderly and children. Some cities aim to retrofit public spaces as part of their heat action plans to make them more useable and thermally safe during extreme heat events. However, cities lack the relevant scientific data to inform such plans and often have no means of evaluating and quantifying the likely benefits from specific redesign strategies. To address this challenge, we evaluated the outdoor thermal regime in Mesa, Arizona, on a human scale. We generated high-resolution Mean Radiant Temperature (MRT) data using surface models developed using LiDAR point clouds and meteorological forcing data from a local weather station. We modified the surface models to reflect future scenarios and exposure settings following the plans for modifying vacant lots in the city. MRT in most vacant lots without shading reaches values as high as 80 °C during the day. We observed that the heat burden was reduced by about half at locations with shading from existing trees. Future work will investigate how the redesign strategies improve the useability of the spaces under different exposure settings.

How to cite: Buo, I., Middel, A., Boateng, E. N. K., Sobhaninia, S., and Solis, P.: Assessing Thermal Comfort in Outdoor Public Spaces: Evaluating Mitigation Strategies for Extreme Heat, 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-585, https://doi.org/10.5194/icuc12-585, 2025.

The RayMan model (www.urbanclimate.net/rayman) 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.

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 and Applications , 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-43, https://doi.org/10.5194/icuc12-43, 2025.

The negative impact of overheating on mortality is well studied, as is the Urban Heat Island (UHI) effect. We also know that urban adaptation measures like increased greenspace and changes to building materials (e.g. cool roofs) have the potential to reduce urban overheating and bring about associated benefits. However, implementation of suitable urban solutions requires careful consideration of a full range of societal costs and benefits which is location specific.

In the context of climate change, more frequent extreme temperatures, and growing urban populations in large parts of the world, urban adaptation is urgently required to reduce dangerous impacts of urban overheating. In order to determine the most suitable adaptation measures to be employed in different urban settings and under different climatic conditions, we require impact assessments which consider environmental, health, and economic aspects.

We use urban climate modelling, coupled with location specific social and demographic data to determine wider impacts of urban adaptations in cities with different climates, e.g. in the UK and India. We present quantification of heat related mortality impacts due to the UHI, and the associated economic costs. We quantify the economic benefits of solutions such as rooftop solar PV panels, which have effects on local temperatures at the same time as providing renewable energy. This work highlights the wider implications of urban adaptation on society, beyond reductions in temperature.

How to cite: Heaviside, C., Simpson, C., Brousse, O., Grellier, J., and Dasgupta, P.: Health, economic and social perspectives of urban adaption measures in the context of climate change, 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-656, https://doi.org/10.5194/icuc12-656, 2025.

Lab-based research has demonstrated a causal relationship between ambient heat and cognitive performance across different age groups. Meanwhile, many older adults often experience cognitive difficulties in their daily life. Yet, it remains unclear how real-world indoor heat exposure influences cognitive abilities in older adults within their own home, where they have at least partial control over the indoor temperature. We conducted a 12-month observational study of 47 community-dwelling older adults in Boston, MA. We continuously monitored participants’ home ambient temperature and sent them twice-daily surveys of self-reported attention difficulties. Overall, we collected 17,201 Ecological Momentary Assessments of attention that were time-synced with sensor-measured home ambient temperature at the time of response. Controlling for humidity and other relevant covariates, the odds ratio of experiencing difficulty keeping attention was lowest within the indoor temperature range of 20 - 24°C. Notably, a 4 °C increase beyond this range doubled (P<0.001) the likelihood of reporting difficulty maintaining attention. These results suggest that even among older adults who have air conditioning and a relatively high standard of living, temperature fluctuations can have detrimental impacts on cognitive well-being. Addressing indoor heat exposure is therefore crucial for protecting older adults’ cognitive functioning against the increase in frequency and intensity of heatwaves.

How to cite: Baniassadi, A., Yu, W., Day, R., Travison, T., Lipsitz, L., and Manor, B.: Indoor Heat Exposure Linked to Reduced Attention in Older Adults, 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-786, https://doi.org/10.5194/icuc12-786, 2025.

Homelessness and heat hazards persist as public health concerns in many cities globally. The concurrence of these two urban challenges exacerbates vulnerability. Responses from local authorities and modified personal behavior are often implemented to enhance resilience. One observed strategy to prevent exposure to direct sunlight is using tent shades. We tested the efficiency of four commonly used tent shades by people experiencing homelessness in the Phoenix area over identical tents (tarp, mylar, white bedsheet, and aluminum foil). We compared them to ambient conditions and a control tent. We monitored meteorological variables at all six locations, notably air temperature (T_air) and the Mean Radiant Temperature (MRT). We applied statistical techniques and physiological modeling to determine the heat experiences of people experiencing homelessness under the sweltering summer conditions for the various shade types. The results show that using tent shading led to a notable reduction in in-tent MRT during daytime hours (p<0.05). However, the shades amplified the risk of in-tent thermal discomfort at night when compared to both the control tent and the immediate ambient conditions. In addition, the choice of temperature metric matters, and using only either MRT or T_air to assess heat experiences in the tents could lead to inconsistent conclusions about in-tent microclimate. We found evidence of higher risk heat strain, with core temperature exceeding 40˚C for users of drugs. We recommend testing the effectiveness of heat-intervening strategies to prevent heat-related illnesses and mortality. Our study does not support the use of tents or shade covers as a viable strategy for heat relief, especially for populations at the highest risk of heat such as people experiencing homelessness.

How to cite: Karanja, J., Vanos, J., Joshi, A., Penner, S., Guzman, G., Connor, D., and Rykaczewski, K.: Tent Shades: Heat Relief or Added Strain for People Experiencing Homelessness? , 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-832, https://doi.org/10.5194/icuc12-832, 2025.

The methods and equipment for the quantification of outdoor thermal comfort conditions have evolved over the past few years. There is consensus about the use of 3 net radiometers as the best way to quantify the mean radiant temperature (MRT) outdoors and MaRTy has been a popular implementation of this concept, with a mobile approach. MaRTY is a mobile biometeorological instrument platform capable of measuring air temperature, humidity, wind speed and direction, GPS coordinates and MRT using data captured in six directions by six solar and six infrared radiometers. These parameters are used to compute the local thermal comfort conditions, simulating the way the human body experiences heat. However, the weather station is commonly placed at 1.5 m and the net radiometers at 1 m above the ground, which describes the conditions relevant to a standing adult but not for a child or a sitting person.

Here, we present a modified setup that allows for the measurement of the air temperature, dew point temperature and wind speed at 0.3 m, 1.5 m, and 1.8 m, and the mean radiant temperature at 0.5 m and 1 m. The latter allows for the measurement of the MRT with different view factors to portions of the ground and of artificial/natural shade, which is particularly relevant for children at playgrounds, where there is not a consistent land cover and shading over a large area. Our measurements show that during weak wind conditions, the air temperature at 0.30 m can be even 1 C higher than at 1.5 or 1.8 m. The wind speed at 0.30 m is also lower than at 1.5 m, as is the relative humidity. These measurements are consistent with the theory of boundary layers near the surface, and they quantify different heat stress exposure for children than for their standing parents/guardians.

How to cite: Paolini, R., Parchami, M., Nazarian, N., and Hart, M.: MaRTy for Kids: Adapting Biomet Equipment to Capture the Heat Exposure of Children, 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-249, https://doi.org/10.5194/icuc12-249, 2025.

Forests have always been undeniably important, but urban forests are now gaining even greater significance in our ever-expanding society, where cities are continuously growing. This is particularly evident in cities like Raleigh in North Carolina, where these green spaces have become one of the city's most appealing features. Throughout history, we have observed disparities in the benefits of these ecosystems across different strata within cities, where the minority and more vulnerable populations bear the burden of a deteriorating urban forest's health and reduced service provision. This study combines spatial analysis with fieldwork, examining various factors such as connectivity, soil conditions, species richness, canopy coverage, dieback, and tree density. These elements were evaluated using the Social Vulnerability Index to determine whether a comparable situation of disparity exists within the tree canopy surrounding Raleigh's attractive trails that fulfill a vital role as recreational areas and protective corridors for water resources. The findings reveal no significant disparity in coverage, wealth, and mortality among vulnerable populations. However, the invasive and vine coverage impacts the health of the urban forest but is not equally distributed in society. This research highlights the need for sustainable management to ensure equitable benefits and continued health of these essential spaces. 

How to cite: Betancourt, A.: Equity and Health in Raleigh’s Urban Forests, 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-60, https://doi.org/10.5194/icuc12-60, 2025.

The urban heat island (UHI), a nocturnal phenomenon characterized by a temperature difference between urban and rural areas in temperate climates, is well-documented in large cities (>500,000 inhabitants) but also occurs in medium-sized cities (20,000–500,000 inhabitants) and small towns (<20,000 inhabitants). While urban vegetation is often considered a solution to mitigate the UHI, it is also affected by it, particularly through an earlier onset of vegetative growth in spring. However, most studies focus on temporal differences or comparisons between urban and rural areas, without thoroughly analyzing intra-urban variations.

With the growing availability of intra-urban temperature monitoring networks, more detailed research on this phenomenon is becoming possible. In the Rennes basin (France), such a network has been deployed in the medium-sized city of Rennes and its surrounding small towns (RUN).

We aim to establish the relationship between the UHI and the spring phenology of tree species. To this end, the vegetative onset of seven species was monitored through in situ observations during the spring of 2021. The responses of the sweet cherry, common maple, and pedunculate oak follow a linear trend, becoming earlier as the percentage of urbanized areas increases. The tree species responded significantly to intra-urban minimal temperature variations, as the UHI was particularly intense during the spring of 2021. The oak showed the strongest response, with its vegetative onset advancing by more than two weeks in Rennes and by over one week in the surrounding towns.

These findings raise questions about the vegetation's cooling capacity earlier in spring and during summer, when water reserves may be reduced due to earlier vegetative activity. They also highlight concerns about the ability of species to sustain activity in an environment with increasingly stressful future conditions in terms of temperature and drought.

How to cite: Brabant, C., Dubreuil, V., and Dufour, S.: Urban heat island and Tree phenology: A spatial relationship, 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-64, https://doi.org/10.5194/icuc12-64, 2025.

Urban environment is a key focus area for tourism activities, where local and micro-scale climatic conditions significantly influence the health, well-being, and behaviour of both tourists and residents. Climate change can alter the spatial distribution of urban areas in terms of their suitability for tourist activities. Consequently, monitoring the impact of climate system transformations on urban tourist destinations is crucial for engaging tourists and stakeholders in effective climate adaptation. However, current regional climate models lack the spatial resolution and detailed representation of local physical processes necessary to adequately capture urban-scale climatic dynamics. For meteorological variables such as air temperature, humidity, and wind speed, higher-resolution outputs derived from land surface models offer more representative and granular insights for impact assessments in urban contexts. In this study, the SURFEX land surface model is employed to assess the impacts of climate change on tourism in Szeged, Hungary. Specifically, the ALADIN-Climate regional model outputs are downscaled with SURFEX to a horizontal resolution of 1 km. Tourism climate conditions are evaluated for the periods 2041–2070 and 2071–2100 using the urban Holiday Climate Index and a modified form of the Tourism Climate Index. Future anthropogenic activities are described under the RCP4.5 and RCP8.5 emission scenarios. The uncertainties in the simulations are addressed through comparative analyses of the different indices, emission scenarios, and periods. The results of this study can contribute to the broader discourse on bioclimatic resilience, emphasizing the need for sustainable urban design and climate adaptation measures that mitigate adverse effects on health and well-being of tourists and residents.

Project no. 142335 has been implemented with the support provided by the Ministry of Culture and Innovation of Hungary from the National Research, Development and Innovation Fund, financed under the PD_22 funding scheme.

How to cite: Kovács, A. and Molnár, G.: Mapping future climate suitability for urban tourism in Szeged, Hungary, 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-69, https://doi.org/10.5194/icuc12-69, 2025.

The addition of irrigated water to regions with naturally limited surface water is bound to have thermal environmental impacts. Recent studies have begun exploring irrigation-induced impacts on heat stress. However, no studies have integrated regional climate and physiological modeling to examine these impacts through meteorological and physiological pathways. To fill this gap, we implemented an irrigation scheme into the Weather Research and Forecasting (WRF) model to simulate irrigation-induced meteorological processes across Arizona cities during the summer of 2023. Then, thermal environmental factors derived from the WRF simulations were input into a human heat balance model to evaluate changes in livability (maximum safe and sustained activity). Our findings showed that, during the day, irrigation led to a redistribution of surface energy budget (a greater conversion of sensible and ground heat into latent heat). Consequently, reduction in air temperature and mean radiant temperature (MRT) offset the negative effects of increased moisture in Phoenix and Tucson, two large semi-arid metropolises, resulting in decreased human dry heat gain and increased livability. Conversely, in Flagstaff and Prescott, two mountainous cities, irrigation increased daytime livability by reducing humidity. Although irrigation slightly decreased nighttime livability, its daytime benefits outweighed the minor drawbacks at night in the four main Arizona cities. This study underlined the value of coupling regional climate and human physiological modeling to quantify summer heat stress variations driven by meteorological and physiological processes.

How to cite: Deng, X., Vanos, J., Guzman-Echavarria, G., and Georgescu, M.: Irrigation in and around Arizona cities: Assessing impacts on urban climate and heat stress through meteorological and physiological pathways , 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-319, https://doi.org/10.5194/icuc12-319, 2025.

India's rich and diverse cultural heritage attracts millions of domestic and international visitors annually. However, the human bio meteorological aspects of these heritage sites remain unexplored areas of tourism. As climate change intensifies temperature extremes and alters seasonal weather patterns, evaluating and improving thermal comfort has become a pressing issue for heritage site managers and policymakers. This study assessed human bio meteorological conditions in a UNESCO World Heritage site in Hampi, India, based on energy budget indices Universal Thermal Climate Index (UTCI) and Physiologically Equivalent Temperature (PET). We conducted microclimatic field observations in summer and winter in four locations in Hampi (Hampi Bazaar Street, Vittala Bazar Street, Royal Center, and Kampa Bhupa's Path). The study reports that Hampi Bazaar Street and Royal Center experience moderate heat stress during winter, with a mean UTCI of 37°C and a mean PET of 40°C.

In contrast, during the summer, Vittala Bazaar Street and Kampa Bhupa's Path face stronger heat stress, with a mean UTCI of 45°C and mean PET of 48°C, compared to the other locations. According to the thermal stress indices, both seasons experience high thermal stress and lack significant outdoor thermal comfort. Results can help formulate strategies to improve the outdoor microclimate of a heritage site.

How to cite: Paul, T., Daketi, S., Rao, K., and Chundeli, F. A.: Exploring Human Bio Meteorological Conditions in a Heritage Site: A case of a UNESCO World Heritage Site in Hampi, India., 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-333, https://doi.org/10.5194/icuc12-333, 2025.

As climate change continues, cities are experiencing more heat and drought, causing further deterioration of growing conditions for urban trees. We investigated the growth of the commonly planted urban tree species Tilia cordata, Acer platanoides and Robinia pseudoacacia. The growth analyses are based on dendrometer data from permanent tree laboratories in two German cities with different precipitation levels: Munich with 940 mm/year and Würzburg with 570 mm/year. Species-specific growth patterns (quantity, growth initiation and duration) and the effects of site microclimate on stem increment were analyzed. Due to the high temporal resolution of the dendrometer data and the long recording periods of over 5 years, both long-term trends over several years and short-term reactions of the trees to external influences can be analyzed.

Additional to the species-specific differences, with lowest annual growth rates for T. cordata, significant trends show that precipitation and urbanization strongly dictate where trees grow the best. For both cities, cooler and greener sites revealed higher stem increment compared to warmer, highly sealed sites in the historic city centre. During 2021 more precipitation was registered (14 to 19% higher than the long-term average) in both cities. The most beneficial effect on tree growth is clearly shown for Munich, with approximately 50% higher increment for A. platanoides and 30% higher increment of T. cordata compared to the drier year 2022.

These results can support planning decisions on the selection of suitable tree species for urban locations.

How to cite: Franceschi, E., Moser-Reischl, A., Rahman, M. A., and Rötzer, T.: Influence of weather and climate on the growth patterns of common urban tree species, 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-374, https://doi.org/10.5194/icuc12-374, 2025.

In the last years, the frequency and impacts of heatwaves have risen significantly, with Spain experiencing a near doubling of these extreme events (Núñez Mora, 2021). In littoral regions, coastal breezes—driven by temperature gradients between land and sea surfaces—can play a crucial role in mitigating extreme temperatures.  This study focuses on the influence of coastal breezes in the southwest of the Iberian Peninsula on thermal comfort during a heatwave period.

Coastal areas have experienced significant urban development, as approximately 60% of the Spanish population lives in these regions (de Andrés et al., 2017). In these terms, urban heat exposure is shaped by meteorological variables that operate across multiple spatial and temporal scales. For instance, in the city, temperature and humidity exhibit variations on scales of hundreds of meters, while the heterogeneity of the wind speed and shortwave/longwave radiation are highly localized, influenced by individual buildings and fluctuating over just a few meters.  

To assess the impact of coastal breezes on thermal comfort, we analyze observational data from meteorological stations and model output from the Weather Research and Forecasting (WRF) model, incorporating the urban parameterization WRF-Comfort (Martilli et al., 2024). This approach enables us to evaluate the thermoregulatory effects of breezes and compare simulated results against observational data, offering insights into mesoscale interactions between urban dynamics and regional climate processes during extreme heat events.  This research highlights the importance of integrating mesoscale modeling with urban processes to better understand climate extremes and their mitigation. Given the strong link between thermal comfort and human well-being, understanding these interactions is essential for developing strategies to reduce heat-related health risks in urban populations.

How to cite: Carbone, J., Luján-Amoraga, E., Ortiz-Corral, P., Sanchez, B., Martilli, A., Sastre, M., Yagüe, C., Alvarez, O., and Román-Cascón, C.: Thermal comfort and the role of coastal breezes during heatwaves in the southwestern Iberian Peninsula: insights from observations and WRF modeling., 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-377, https://doi.org/10.5194/icuc12-377, 2025.

Urban forests are an essential component to livable cities and provide important services to residents. Many of these benefits are dependent on when and how long leaves are on the trees which is determined by their leaf phenology. The transition between phenological phases, including new leaf growth and senescence, is triggered by climatic cues such as light, temperature, and water. However, the specific combination of drivers can vary by species and climate region. The high species diversity and surface heterogeneity of urban areas has made city-wide phenology research challenging. In water-limited Mediterranean climates, precipitation has been shown to be an important driver in natural ecosystems; however, it is unclear whether this is also true in urban landscapes. To understand how climate change may influence phenology in a Mediterranean climate city, we used high resolution PlanetScope satellite imagery from 2018 to 2024 to monitor more than 35,000 species-identified trees in Santa Barbara, California, USA. We found the 3m resolution suitable to study individual trees and successfully detected seasonal NDVI fluctuations in evergreen species, which were validated with field observations. In our image time series, 81.8% of the deciduous tree population and, notably, 69.1% of the evergreen tree population had at least one annual phenology cycle that was detected. We found that trees were sensitive to precipitation, with spring rain delaying the end of the season by 2.25 days/cm on average across species. Warm fall temperatures delayed the green-up date whereas warm winter temperatures led to an earlier green-up. These results build upon methods to study urban forests of semi-arid climates and deepen our understanding of how changing climatic patterns may affect the leaf phenology and productivity of these species.

How to cite: Dixon, A., Alonzo, M., Roberts, D. A., and McFadden, J. P.: Urban Tree Phenology Sensitivity to Precipitation and Temperature in a Mediterranean Climate City, 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-502, https://doi.org/10.5194/icuc12-502, 2025.

In the first month of 2025, the city of Rio de Janeiro recorded 1,012 dengue fever cases, reaffirming the disease as one of the municipality's major public health challenges. Considering the close relationship between the disease vector and meteorological and climatic conditions, this study investigated the correlation between the climatic morphologies and the infestation by Aedes aegypti, the primary vector of the arbovirus. To achieve this, infestation indices were calculated, including the egg density index and the ovitrap positivity index, based on data collected from traps managed by the Municipal Health Department. Additionally, the Local Climate Zones (LCZs) were mapped in the study area, which were subsequently correlated with infestation data through multiple linear regression and Spearman tests. For a better understanding of the processes involved, the climatic characterization of the LCZs was conducted using meteorological data obtained from eight stations of the AlertaRio System: Vidigal, Irajá, Jardim Botânico, Barra/Rio Centro, Guaratiba, Santa Cruz, Alto da Boa Vista, and São Cristovão. Generalized Linear Models (GLM) were applied to correlate the incidence of reported dengue fever cases, infestation indices, and the LCZs. The results indicated high hatching rates of collected eggs, confirming the endemic nature of the disease. Statistical analysis revealed a positive and statistically significant association between the increase in infestation indices and temperatures, particularly minimum temperatures. It was also observed that the compact high-rise, mid-rise, and low-rise typologies showed greater susceptibility to mosquito presence. This result can likely be attributed to a combination of factors, such as reduced ventilation, greater heat retention, and increased availability of breeding sites in densely built urban spaces, favoring the development and proliferation of the vector. The findings reinforce the importance of climate-oriented urban planning in mitigating dengue transmission, providing insights for more effective vector control strategies. 

How to cite: Oscar Júnior, A. C., Mendonça, F., Soek, F. J., and Lins de Carvalho, S.: Urban Climate and Dengue Fever: Assessing Aedes aegypti Infestation across Local Climate Zones (LCZs) in Rio de Janeiro (Brazil), 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-559, https://doi.org/10.5194/icuc12-559, 2025.

The recent increase in global temperatures, coupled with ongoing urbanization, has led to more frequent and severe heat waves in urban areas, posing significant health risks to urban populations. This study investigates the prediction of walking thermal comfort using machine learning models built from experimental data. Field measurements and surveys were conducted with 28 participants in hot summer while they walked along a designated route that included open spaces, tree shade, and artificial shade. Three sets of predictors were evaluated using machine learning models: physiological parameters, microclimate conditions, and a combination of microclimate, physiological, and personal factors. Among the physiological models, those incorporating tympanic temperature consistently outperformed models based solely on skin temperatures. In particular, a k-nearest neighbors (KNN) model using calf, chest, and tympanic temperatures achieved the highest accuracy of 73.3%. In contrast, models using only microclimate conditions reached a maximum accuracy of 66.7% with the KNN algorithm, underscoring the stronger predictive power of physiological indicators for walking thermal comfort. Moreover, integrating microclimate, physiological, and personal factors did not yield improved performance over models using physiological parameters alone. These findings highlight the critical role of tympanic temperature in thermal comfort prediction and suggest that focused physiological measurements may offer a more effective approach than broader environmental or combined models. Further research is needed to explore the underlying mechanisms and validate these results across diverse populations and settings.

How to cite: Ren, G., Tan, Z., and Ouyang, W.: Evaluating Walking Thermal Comfort in Urban Spaces Using Machine Learning: The Role of Physiological and Microclimate Factors, 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-868, https://doi.org/10.5194/icuc12-868, 2025.

Seasonal mortality patterns are influenced by a complex interaction between climatic factors, such as temperature variability, and epidemiological factors, such as the incidence of influenza-like illnesses (ILI). However, the extent to which year-to-year variations in mortality attributable to cold weather and seasonal influenza affect population vulnerability to extreme temperatures in subsequent warm seasons remains poorly understood.

This study aims to assess the interaction between cold-season temperature variability and influenza activity on excess mortality in both cold and warm seasons. Specifically, we investigate how cold-season mortality patterns, driven by non-optimal temperatures and varying levels of ILI incidence, influence population vulnerability to extreme heat in the following summer.

We utilize daily weather and mortality data sourced from the EARLY-ADAPT dataset for the European region, along with weekly ILI counts obtained from the ERVISS surveillance system, spanning multiple years. Epidemic seasons were classified into high, moderate, or low influenza activity based on ILI thresholds (>67th, 33rd–67th, and <33rd percentiles, respectively). Using a two-stage mixed-effect meta-regression analysis, we investigate associations between temperature, influenza activity, and excess mortality during the cold season, as well as their potential influence on heat-related mortality in the following warm season.

Preliminary analyses suggest that the interaction between influenza incidence and low temperatures amplify seasonal mortality risks. This research sheds light on the complex relationship between climatic variability, respiratory infections, and seasonal mortality patterns, offering valuable insights for developing more effective public health strategies to mitigate temperature-related risks. These findings underscore the importance of integrating epidemiological and climatic data to enhance public health adaptation strategies in the face of climate change.

Keywords: DLNM, seasonal mortality, influenza, heat stress, temperature variability

How to cite: Borisova, E., Urban, A., Janoš, T., and Ballester, J.: The compound role of temperature and influenza in seasonal mortality patterns in Europe , 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-281, https://doi.org/10.5194/icuc12-281, 2025.

Low-income areas in developing countries face the challenges of resource inequality and uneven distribution of growth. Under one such circumstance, extreme weather events can cause significant heat stress and heat-related mortality and morbidity if adaptation and mitigation strategies are not designed appropriately. Outdoor occupants are especially vulnerable to this, such as outdoor vendors, athletes, pedestrians, and travelers. In one such context, we seek to explore the thermal comfort perception of elderly adults in the hot-arid city of Jodhpur,India using microclimatic observation, questionnaire surveys and health data from wearable devices. Jodhpur exhibits extreme heat conditions with summertime high air temperatures frequently reaching upto 48^OC. We conduct a random sampling of over 400 people aged over 50 with self-reported healthy conditions willing to travel in public transport. A subjective questionnaire survey involves collecting information on travel patterns, and outdoor thermal comfort perception, supported by objective microclimatic field observation collected using Kestrel 5400 heat stress trackers. We simultaneously collect corresponding health data (SPO2, heart rate, and skin temperature) from wearable devices. Further, through statistical data analysis, we identify personal, socioeconomic, physiological, and psychological variables impacting thermal comfort perception and travel mode choice. We further enumerate the acceptable and neutral thermal range for the elderly commuters from this. We report that the acceptable and neutral thermal range of Physiologically Equivalent Temperature (PET) is much higher in Jodhpur compared to other existing studies from hot-arid cities. We also report that socio-economic, and psychological factors impact the travel mode choice and outdoor thermal comfort perception significantly. The results obtained from our study can aid in formulating strategies for heat-resilient transit infrastructure design. The focus is on identifying and developing data-driven evidences to support formulating an appropriate heat risk assessment framework to ensure optimum thermal conditions for the elderly commuters during outdoor trips while using public transit.

How to cite: Banerjee, S. and Kumar Singh, A.: Assessing the outdoor biometeorological conditions of the elderly commuters in a hot-arid desert city of Jodhpur, India, 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-1048, https://doi.org/10.5194/icuc12-1048, 2025.