Spatial and temporal climatic characteristics of hail from 1974 to 2013 in Gansu province

Using hail data at 80 weather stations in Gansu province during 1974-2013, spatial and temporal characteristics of hail days were analyzed.The results show that the large value centers of hail days are located in Maqu, Wushaoling, Huajialing, Subei and Mazongshan, which is similar to elevation change.Hail weather often occurs in Gannan Plateau, Linxia, Wuwei areas during April to October, especially in Minxian station in April and Maqu station during May to October.It is in a decreasing trend for hail days in the recent 40 years, especially in Hedong region, and two low value centers are in Minxian-Gannan Plateau and Mazongshan.Number of hail days is reduced significantly since 1995 and has a 3.3 years cycle.