Abstract Body

It is now widely recognised that sustainable urban planning and development must take the outdoor thermal comfort of city dwellers into consideration. One of the most important bioclimatic design elements for thermal comfort is greenspace. Relatively few studies have explored the potential of mobile thermal comfort measuring methods, despite the benefit of improved spatial coverage that they offer. In the present study, we collect averaged microclimate data from transects within a large number of sites. We demonstrate how local physical characteristics of the sites; Sky View Factor (SVF), tree shade, surface cover, and canyon effect, contribute to human exposure to potentially uncomfortable thermal conditions as expressed via thermal comfort indices (Universal Thermal Climate Index, UTCI). A total of 126 sites were visited in the hot summer of 2020, of which 79 were green. Varying levels of SVF and tree cover in the sites allowed the construction of multivariate models which revealed that decreases of SVF by 12.5 % and increases of tree cover by 25 % can reduce the UTCI by 1 degree. Such quantitative relationships may prove useful for practitioners aiming to improve the thermal comfort of outdoor spaces. The only sites reaching comfortable UTCI categories were streets with trees and public gardens.The mobile methodology has proved useful for investigating a large number of sites from the point of view of the pedestrians that use those spaces, and future studies could benefit from application and modification of this approach.