Climatology of Hail in China: 1961-2005

A previous hail climatology of China was based upon observations during 1951-60. An effort has been made in this study to update this hail climatology in China with the use of a much longer record of observations from 1961 to 2005. This is made possible with the release of a new, comprehensive collection of hail observational data in May 2006 by the National Meteorological Information Center of China. The focus herein is to document the mean annual geographical distribution of hail frequency and seasonal and diurnal variations of hail occurrence. The results show that hail occurs most frequently in the high mountainous areas and northern plains. As a result, hail frequency is generally higher in northern China than in southern China. The hail frequency is highest over the central Tibetan Plateau. Hail seasons start in late spring and end in early autumn in northern and western China; they start mainly in spring in southern and southwestern China. On the diurnal time scale, hail events occur mainly between 1500 and 2000 local time in most of China except in Guizhou and Hubei Provinces (central western China), where hail events often occur during nighttime.