Capturing the cooling benefits provided by large parks on surrounding neighbourhoods’ temperatures using low-cost commercial sensors in east London

Parks are protective against hot temperatures in urban environments, providing shelter from extreme heat and heat stress to local populations. Nevertheless, little is known about the capacity of large parks to cool down surrounding neighbourhoods through advection of cooler temperatures. Because of the characteristic data scarcity in urban environments, most of our current understanding of heat advection comes from modelling studies, preventing us from accurately assessing the impact of large green areas, like parks, on urban climates.

By deploying a set of 40 low-cost air temperature and relative humidity sensors with radiation shields across the large Olympic Park and surrounding neighbourhoods in the east of London we: (i) test the applicability of low-cost commercial sensors to complement existing weather sensor networks (e.g., MIDAS and Netatmo) for urban climate studies; (ii) assess how each of the studied urban environments are exposed to heat-stress during the summer of 2024; and (iii) quantify how much of a cooling was provided by the Olympic Park depending on different synoptic conditions derived from ERA5 reanalysis.

Using socio-economic data from the 2021 Census alongside a set of heat stress indices derived from our records in air temperature and relative humidity (e.g., Wet-bulb globe temperature and Heat Index) we also provide a deeper understanding of the type of population that benefited the most from the cooling brought by the park. In addition, we check whether water vapour added by the vegetated area was beneficial or detrimental to local populations.

Our research has important implications on the added value of dense urban weather sensor networks for monitoring urban heat stress and for future urban green designs aimed at adapting to extreme heat.