Assessing summer thermal environment in humid cities: Local climate zone perspective

Single land surface temperature (LST) cannot accurately characterize the high temperature and humidity inside cities due to climate warming. Studies on changes in hot and humid urban environments have gradually used near-surface air temperature and humidity. The present study, applying the theory of local climate zones (LCZs), showed that the distribution features of hot humid urban environment and variations across time and space, both at the surface and near-surface level, could facilitate analysis of the evolution of summer heat climate in high-humidity municipalities. According to the results, from 2013 to 2022, the average LST increased by 6.15°C. LCZ8, LCZ10, and compact LCZs were the main warming areas. Relative humidity had a considerable cooling influence on the near-surface temperature but had no discernible effect on LST. Temperature of the wet bulb in the city center was lower than in the suburbs, and those in LCZs 1-3 were higher than those in LCZs 4-6.