Abstract:By using hourly rainfall data of 1426 national stations and regional stations in the warm season (from May to September) in Zhejiang Province from 2010 to 2019 and NCEP 1°×1° reanalysis data four times a day, the short-term heavy rainfall, the extreme short-term heavy rainfall, regional short-term heavy rainfall events in the warm season are analyzed. The results show that: (1) In recent ten years, the interannual variation of short-term heavy precipitation frequency in the warm season showed an increasing trend; and the variation of precipitation intensity was stable. The precipitation frequency was the highest in early August. The intensity was the strongest in middle September. The precipitation frequency was the highest from 16:00 to 19:00, and the intensity was the highest at 16:00 and 20:00. The spatial distribution of short-term heavy rainfall frequency and intensity was closely related to the topography, and short-term heavy rains were prone to occur in the mountainous areas of coastal areas. (2) In recent ten years, the frequency of extreme short-term heavy precipitation in the warm season had great interannual variation. Still, the annual variation trend was stable. The precipitation frequency was the highest in late August, and the precipitation intensity was the highest in middle and late September, while the precipitation frequency at 16:00 was the highest. The precipitation intensity at 12:00 was the highest. The spatial distribution of extreme short-term strong precipitation frequency was also related to the topography, and the frequence in the coastal area was greater than in inland. (3) Regional short-term heavy precipitation events could be divided into cold shear, warm shear, tropical cyclone, high trough, and subtropical high control types.