Modeling the relationship between the urban development and subsurface warming in seven Asian megacities

•Simulating of urban subsurface warming related to urbanization in 7 megacities.•Aiming to quantify subsurface warming by changes of LU in early modern times.•Tsfc of a calm and clear day in summer increased by about 1.1 K 100 y−1.•Suburbs of Bangkok with a big LU change have been a more rapid increase of Tsfc.•Seasonal climate variability of Tsfc is studied, considering the annual average.