Comfort in the canopy: How urban treescapes affect human thermal comfort in a temperate climate

1. People living in urban centres are exposed to higher levels of heat stress thanthose living outside of these areas; this is intensified by the urban heat islandeffect. Heat stress is a concern for the more vulnerable members of society andcan exacerbate many medical conditions; excessive heat increases morbidity andmortality rates. Green infrastructure can help to mitigate against excessive urbanheat and provide more thermally comfortable environments. 2. This paper presents data from a high spatial and temporal resolution microclimatesensor network in the city of Leeds, United Kingdom. Sensors are installed in greyspaces and green spaces, including small city centre parks, large suburban parksand treescapes. Analysis focuses on two summer periods (June–August 2023 and2024). 3. These data demonstrate that treescapes offer the greatest relief from excessiveurban heat when compared with other greenspaces. Urban treescapes were amean of 1.4°C cooler than surrounding grey spaces, compared with a differenceof 0.7°C between parks and grey spaces. During peak air temperature periods,parks were up to 2.8°C cooler, and treescapes were up to 5°C cooler than greyurban spaces. 4. Universal Thermal Climate Index calculations demonstrate that the urbantreescapes consistently provide lower exposure to heat stress; when sub-canopysolar radiation levels are considered, treescapes expose citizens to 96% fewerhours of strong heat stress and 64% fewer hours of moderate heat stress thanurban grey spaces. 5. Results presented in this paper support the retention and expansion of urbangreenspaces and urban treescapes; specifically, they also have important impli-cations for a range of associated issues including citizen health and well-being,inclusive, just access, urban planning and policy development.