Shade is a critical urban design feature for mitigating heat stress, particularly in hot, arid cities. Its impact on pedestrians is highly localized, site-specific, and dependent on multiple factors, including shade type, orientation, and ground cover. As cities strive to address "shade deserts"—urban areas lacking adequate shade infrastructure—decision-support tools are needed to inform optimal shade placement and design. We developed a web-based decision-support tool that generates shade performance curves to evaluate the cooling efficacy of various shade types. Users can customize parameters such as shade type, size, location, and date to assess their effectiveness in reducing heat load. The tool displays a rendered hemispherical view of the shade structure and a graph illustrating the hourly reduction in mean radiant temperature (ΔMRT) compared to a sun-exposed location. We validated the tool using MaRTy, a human-biometeorological cart, for hot, sunny summer days in Phoenix, Arizona. Sun-exposed locations had an RMSE of 5.9°C and an MBE of -4.2°C. Umbrella shade was underestimated systematically (MBE = -4.39°C) with an RMSE of 6.0°C. Tree shade was modeled with an RMSE of 5.1°C and a lower bias (-2.0°C). Shade performance varied by ground type, with concrete yielding the best accuracy (RMSE = 4.0°C, d = 0.86), while grass exhibited greater variability. A sensitivity analysis was conducted to investigate shade performance across shade types, seasons, and times of day. The web-based decision-making tool will allow users to assess the heat load impacts of customized, site-specific shade interventions for active shade management, offering planners and designers a robust tool for strategic shade implementation.

How to cite: Middel, A., Guzman, G., and Khan, W. H.: Online Decision-Making Tool for Active Shade Management, 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-955, https://doi.org/10.5194/icuc12-955, 2025.

Tree planting is often regarded as the main urban strategy that can provide extensive distribution of outdoor shade. However, the physical constraints that limit the provision of adequate underground soil volume alongside the slow development of shade-providing tree crowns sometimes make artificial shading elements the only viable option for effective shading. Despite their importance for outdoor climatic design, few studies have assessed the magnitude and quality of heat stress relief provided by common artificial shading systems compared to tree shade, and a widely accepted methodology for evaluating the efficacy of different types of artificial shading systems is still missing. 

In this study, we attempted to develop a systematic analytical method for artificial shading performance based on the geometry and material properties of the elements and the resulting solar transmittance, heat emittance, and overall heat comfort provision in the shade they produce. For this purpose, we monitored the performance of common artificial shading systems under summer, clear-sky conditions in Tel Aviv-Yafo. Monitoring was done using an on-site compact weather station and Chaosense units measuring Mean Radiant Temperature, which enabled us to calculate the degree of thermal stress mitigation using the PET and UTCI indices. The data was collected under a wide variety of artificial shading elements simultaneously with monitoring the conditions at adjacent non-shaded, tree-shaded, and building-shaded locations. 

The monitoring results showed that the performance of non-uniform opaque shading surfaces, such as louvred structures, depended on their geometry and orientation, with optimal performance occurring when the openings in the shading surface are minimal. With uniform shading surfaces, primarily textile-based, we found a large variance in cooling efficacy that mainly resulted from the degree of direct solar transmittance through the shading surface. However, even the least effective uniform artificial elements still demonstrated a considerable reduction in heat stress compared to non-shaded locations.

How to cite: Elmaliah, A. and Aleksandrowicz, O.: Performance-based evaluation of artificial shading systems for heat-stress relief in outdoor environments, 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-372, https://doi.org/10.5194/icuc12-372, 2025.

Assessing shading benefits in urban environments has often been a complex task. This study proposes a simplified method for evaluating outdoor thermal comfort using the RayMan regression model to calculate Physiologically Equivalent Temperature (PET) and Mean Radiant Temperature (Tmrt).

By comparing Solar Radiation Transmissivity (SRT) with the Leaf Area Index (LAI) of common tree species in Taiwan, the study identifies an average SRT value of 0.3 (range: 0.2–0.5). This value is incorporated into ArcGIS solar radiation simulations to adjust sub-canopy radiation, enabling the construction of urban shading maps and PET-based thermal comfort maps for sidewalks. Additionally, the study analyzes PET along selected pedestrian pathways to assess heat stress conditions.

The results reveal a strong correlation between PET values derived from the simplified model and those obtained using the RayMan model. Radiation, wind speed, and air temperature are identified as the primary climatic factors influencing thermal comfort in Taiwan. Furthermore, the strong relationship between SRT and LAI significantly enhances the accuracy of thermal comfort mapping.

This GIS-integrated approach effectively identifies shading deficiencies, evaluates shading benefits, and recommends comfortable walking routes. The findings demonstrate that strategic shading can lower PET by 1–2°C in urban outdoor spaces, highlighting the crucial role of shading in enhancing outdoor thermal comfort.

How to cite: Lin, T.-P. and Wu, Y.-C.: Simplified Outdoor Thermal Comfort Assessment Using Urban Shade Maps, 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-145, https://doi.org/10.5194/icuc12-145, 2025.

Shade provision by buildings and trees is very beneficial in reducing pedestrian heat stress in hot climate regions, such as the Mediterranean. However, shade is not constant in time and space, which makes difficult to understand its actual potential to reduce pedestrian heat stress depending on the geometry and orientation of each urban space and the time of the day.

In this work we present a framework to generate district-scale heat stress frequency maps based on the spatiotemporal variability of mean radiant temperature at the street level. This allows understanding the beneficial effect of a district urban geometry and vegetation on the thermal conditions of its urban spaces, as well as to identify where and when more shade is needed to reduce pedestrian heat stress.

The approach is applied to the Gràcia district of Barcelona. First, we carried out high-resolution simulations of the radiation fluxes across the urban area using the SOLWEIG model. Then we correlated the Mean Radiant Temperature (Tmrt) to the PET values in the same points, to identify threshold values corresponding to different heat stress levels. Finally, we cross compared the spatial (maps) and frequency (histogram) distribution of Tmrt values across the whole district over different times of the day.

The results indicate that shade provision by urban geometry reduces pedestrian heat stress from extreme to moderate levels in the morning (until 12:00 local time) and afternoon (starting from 16:00). In the time window from 13:00 to 15:00, urban geometry has negligible impact due to high solar elevations, while trees shades significantly reduce heat stress from beyond extreme to moderate levels.

Based on the results, we generated a cumulative heat stress frequency map that can be used as a practical tool to plan district-scale shading interventions enabling acceptable thermal conditions across the whole urban area.

How to cite: Salvati, A., Colaninno, N., Lopez-Besora, J., and Morganti, M.: How much shade do we need to reduce pedestrian heat stress? Understanding the spatiotemporal variation of the urban thermal environment at the district-scale, 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-654, https://doi.org/10.5194/icuc12-654, 2025.

Urban environments are increasingly shaped by the need to mitigate heat stress, yet the role of shade in this context remains understudied. While it is well understood that shade can significantly reduce thermal exposure, cities lack standardized methods to assess how shade is distributed and whether it aligns with public need. This study investigates the extent to which Amsterdam provides meaningful shade in areas of high social and functional importance, combining geospatial analysis with socio-demographic and network-based approaches.

Recognizing that people engage with urban spaces in different ways, we distinguish between shade for movers (pedestrians, cyclists, commuters) and dwellers (those using public seating, plazas, and gathering spaces), as each requires different forms of shade provision. We analyze shade availability across various public spaces, distinguishing between green (tree) and grey (building) shade, and examine how access varies based on socio-economic and demographic factors. Using a graph network model, we identify key pedestrian routes and public areas where shade provision is most critical.

By integrating spatial, environmental, and social data, this research advances methodologies for evaluating shade distribution and its role in urban climate adaptation. The findings will inform strategic municipal planning, supporting targeted interventions to enhance shade equity and ensure urban infrastructure prioritizes thermal comfort for all residents in Amsterdam and beyond.

How to cite: Beuster, L., Venverloo, T., García-Sánchez, C., Duarte, F., and Ledoux, H.: Shady Politics: Mapping Inequalities in Urban Shade Distribution, 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-793, https://doi.org/10.5194/icuc12-793, 2025.

Urban shade is critical for mitigating pedestrian heat stress and improving thermal comfort, particularly in hot urban environments with intense solar radiation during summer. Traditional urban design practices often focus on overall shadow coverage ratios, which evaluate shading at the site scale rather than along specific pedestrian pathways. However, these approaches fail to adequately address the dynamic shading needs of pedestrians, whose thermal comfort is influenced by exposure patterns along their whole-trip. Based on the thermal comfort requirements of pedestrians during their trips, this study introduces two shade design control metrics: Pathway Shading Ratio and Maximum Allowable Continuous Sunlit Distance. Pathway Shading Ratio quantifies the proportion of shaded segments along a specified walking path, providing a baseline for the minimum shading quantity required across the entire route. Maximum Allowable Continuous Sunlit Distance defines an upper limit for the uninterrupted distance pedestrians can be exposed to direct sunlight, reflecting the temporal and spatial thresholds necessary to maintain acceptable thermal comfort during walking trips. By integrating field-based thermal comfort experiments with simulation analyses, this study systematically derives and quantifies these metrics. The findings establish a framework for targeted shading interventions, bridging the gap between urban shading design and pedestrian thermal comfort needs. This research refines urban shade evaluation systems, enhancing pedestrian thermal environments and providing actionable guidance for urban planners and policymakers to create thermally comfortable and walkable cities.

How to cite: Zhao, H., Xu, G., Xu, Y., Zhao, L., and Meng, Q.: Path-based Urban Shade Metrics: Integrating Pedestrian Thermal Comfort into Urban Design Guidelines, 12th International Conference on Urban Climate, Rotterdam, The Netherlands, 7–11 Jul 2025, ICUC12-213, https://doi.org/10.5194/icuc12-213, 2025.