Abstract:The historical severe convections from 2006 to 2015 in the warm season were classified into three types, namely hail, thunderstorm gale and short-term heavy rain, occurring at the national meteorological automatic stations in Henan Province. The physical parameters and their 15 d moving average values are calculated based on ECMWF reanalysis data, indicating the environmental characteristics such as vapor, thermal and dynamical conditions, and then the monthly characteristics are comparatively analyzed with the key parameters to classify convections selected, considering the influence of monthly change and the variety of climate background. The results showed that the frequency of short-time severe precipitation is the highest while that of hail is the lowest. All kinds of severe precipitation mainly occur in the afternoon (14:00 BT-20:00 BT). The inter-monthly variation of parameters is so prominent that the different parameter thresholds are advisable in the potential forecast monthly. The parameter deviations from the moving climate mean are also valuable for the classification and obviously vary in the different environmental conditions. The monthly characteristics of most parameters for the short-time severe precipitation are significantly distinct from the hail, such as the larger indices of precipitable water, ground dew point temperature, K index, 0℃ and -20℃ level heights, stronger vertical wind shear, convergence and positive vorticity in the lower level, and the less temperature difference between 850 and 500 hPa and CAPE. Most parameters for hail are similar to those of thunderstorm gale with less precipitable water and ground dew point temperature, lower 0 ℃ and -20 ℃ level heights, and stronger convergence and positive vorticity in the upper level, especially in July and August.