Abstract: Using the sounding data from Ankang, Enshi and Wuhan stations from January 1, 2005 to December 31, 2021, and the ground observation and disaster data in Hubei Province during the same period, we analyzed and discussed the seasonal variation of the height of wet blub zero （WBZ） and the height difference between dry blub zero （DBZ） and wet blub zero （WBZ） in different regions of Hubei Province. The seasonal variation of the difference between DBZ and WBZ heights is much smaller than that of WBZ heights, and it is the largest in autumn in east Hubei, the largest in summer in northwest Hubei, and the largest in summer in southwest Hubei. The frequency of WBZ height in each season shows that the probability of WBZ height in spring and autumn is 2 500~ 3 500 m. The WBZ height in summer is significantly higher than that in other seasons, and the lowest in winter. The probability of occurrence of DBZ and WBZ height difference in each season is seen： the probability tends to decrease with increasing height, and the maximum probable height of DBZ and WBZ height difference in spring, autumn and winter are all below 500 m. The synthetic analysis of the main hail weather processes in different regions of Hubei shows that the largest WBZ variation when there is hail occurs in southwest Hubei and the smallest in northwest Hubei. The highest average WBZ height when hail occurs is in southwest Hubei. The DBZ and WBZ height differences are in descending order in Northwest, East and Southwest Hubei.

Key words: hail, zero layer height, melting layer, Hubei Province