Abstract:Since the year 2000, continuous heatwave events have some new characteristics, such as high frequency, long duration, broad influence, strong intensity and high extreme temperature. Analyzed the four times of continuous heatwave weather by use of the NCEP data and synoptic meteorology method, it was found that continuous heatwave weather over north area of Hangzhou Bay seems to appear under the intense warming by descending drafts and clear sky radiation, which is due to the powerful control of the subtropical high with ridge line strengthened up to 30°N, and high and low altitude negative vorticities have a vertical superimposition when the South Asian high moves eastwards, or in the influence of typhoon periphery circulation, and the advection warming, also synthesizing the earlier period continuous high temperature factors. In the 21st century, during the heatwave days, the high temperature hours and extremely hot hours are both growing up, and the latter grows up more. Although the sunshine hours decreased, the temperature still quickly elevated, maybe it is connected with the urban heat island effect (UHIE) which is caused by the development of cities. Nowadays, this effect of cities over the north area of Hangzhou Bay is already extended to the temperature difference relations among cities.