Study on the Urban Heat Island in Sofia City: Numerical Simulations with Potential Natural Vegetation and Present Land Use Data

•There is a significant urban heat island (UHI) in Sofia City in July.•Changes of natural vegetation into current land cover is evaluated with the WRF model.•At night, the temperature increases by 3.4 °C in the central part of Sofia City.•The impact of land use change increases the nocturnal temperature by 82%.•The anthropogenic heat releases cause nocturnal temperature increases of only 18%.