Based on the temperature, precipitation and other observation data at 4 meteorological stations in central districts of Chongqing from 1980 to 2019 and typical time period satellite data, the temporal and spatial variation characteristics of urban heat island effect in Chongqing and the effects of different weather conditions on heat island were analyzed. The results show the urban heat island effect in Chongqing has had an obvious upward trend since the mid-1990s, reaching its strongest in the 2010s. But there has been a slowing down sign in recent years. The diurnal variation of the heat island was weak in the daytime and strong at night. The monthly variation of it was the strongest in August and the weakest in June. The seasonal variation of it was the strongest in mid-summer, followed by early spring, the weakest from mid-spring to early summer. Satellite remote sensing showed the urban heat island appeared a distribution with northeast to southwest. The strong heat island mainly located in dense population areas, such as traditional old city areas, business districts, stations, squares, industrial parks and new urban districts, etc. In the 2010s, the urban heat island in Chongqing is affected by the negative driving factors such as rainy days and cloudy days, and the positive driving factors such as partly cloudy days and sunny days. The average heat island intensity on rainy, cloudy, partly cloudy and sunny days were 0.19, 0.52, 0.69 and 0.76 ℃， respectively.