利用冰雹实况资料、高空探测资料、地面观测资料和EC细网格数值预报资料，统计分析了2012—2021年79次对山东造成较大灾害的冰雹过程的时空分布特征，总结了不同区域、不同大小以及关键月份降雹的关键环境参量特征及阈值。结果表明：①山东降雹具有明显的时空分布特征，降雹主要出现在鲁中地区和鲁北地区；降雹日数年际变化较大，最多年份可达14 d，最少仅为5 d；降雹主要出现在春末夏初，占全年降雹日数的65%；14:00—20:00是冰雹高发时段，占全天降雹的63.3%。②鲁中地区年平均出现大冰雹的次数最多，但半岛地区出现大冰雹的概率更大；大冰雹主要出现在5—6月，占全年大冰雹日数的68.6%。③山东降雹具有较大的对流有效位能、中等及以上强度的深层（0～6 km）垂直风切变、显著的条件不稳定层结和适宜的特征层高度/厚度。④不同区域、不同大小以及关键月份的物理参量的特征和潜势预报阈值都有一定的差别，主要体现在内陆地区、6月降雹、大冰雹较沿海地区、5月降雹、小冰雹的对流有效位能明显偏大、干暖盖指数偏小、深层垂直切变有所增大、抬升凝结高度略偏高、-20～0 ℃层的厚度偏薄。
The temporal and spatial distribution characteristics of 79 hail processes causing major disasters in 2012-2021 are statistically analyzed by using hail data, radiosonde observation data, ground observation data and EC thin grid data, the characteristics and thresholds of key environmental parameters of hails in different regions, sizes and months are summarized. The results show that (1) Hails in Shandong have obvious spatial and temporal distribution characteristics, and mainly appear in central and north Shandong. The number of hail days varies greatly from year to year, with a maximum of 14 days and a minimum of 5 days. Hails mainly occur in late spring and early summer, accounting for 65% of hail days in the year and 65% of hail days in the year. Hails frequently occur from 14:00 to 20:00, accounting for 63.3% of the total hail. (2) The average annual occurrence frequency of large hails is the most in central Shandong Province, but the probability of large hails is greater in the peninsula region. Large hails mainly appear in May and June, accounting for 68.6% of the annual number of large hail days. (3) Hails in Shandong have large convective effective potential energy, deep (0 to 6 km) vertical wind shear with medium or above intensity, significant conditional unstable stratification and suitable characteristic layer height/thickness. (4) Different regions, different sizes and key months have certain differences in the characteristics of physical parameters and potential prediction thresholds. Compared with hail falling in coastal areas and in inland areas, hail falling in June and May, large and small hails, it is mainly reflected in the obvious larger convective effective potential energy, smaller dry and warm cap index, greater deep vertical shear, slightly higher lifting condensation height, and thinner thickness of -20 ℃ to 0 ℃ layer.