Abstract:Based on the results of the field observation experiments that the influence of urbanization on air temperatures reached the greatest on calm, cloudless nights and is reduced in windy, cloudy conditions, homogenized daily minimum temperature datasets for the period 1960—2008 at meteorological stations over East China are analyzed separately for windy, cloudy and calm, cloudless conditions, and their trends are compared. There is a weak tendency of more warming in calm, cloudless days than in windy, cloudy days in East China(20-45 °N,110-125 °E), the difference 003℃ per decade is attributable to urbanization. Furthermore, the urban caused warming from 1979 to 2008 is estimated to be 066℃ per decade. The warming caused by urbanization is always found to be smallest in summer in both East China or areas of city agglomeration, such as Jingjintang area, Yangtze River delta and Pearl River delta.