Abstract: Based on the daily precipitation data observed by 17 meteorological stations in Shijiazhuang, the variation of rainstorm days was analyzed, and the distribution of extreme values of precipitation in different periods was studied using the means of Gumbel I extreme value distribution. The results showed that the rainstorm days decreased gradually from the northwest and the southeast to the central area of Shijiazhuang, and most rainstorm days occurred in the northwest. The rainstorm days decreased in most areas in recent decades, but it increased in the north. There were the obvious annual and decadal variations of rainstorm days in Shijiazhuang. The rainstorm days were more during the period from the mid-1970s to the early 1980s and around the mid1990s since the 1970s. There were the 6-year and 16-year fluctuation periods of rainstorm days in the study area. The differences of maximum daily precipitation and maximum precipitation in a continuous precipitation process between the 10-year, 30-year and 50-year periods were high, especially in the northwestern and southwestern mountainous areas. The maximum daily precipitation at all the meteorological stations was higher than 100 mm.

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