Based on the observation data such as radar, rainfall and radiosonde, the precipitation enhancement effect of the warm cloud-seeding experiments using hygroscopic flares at Bawangling, Changjiang and Maoyang, Wuzhishan in Hainan Island from 2015 to 2020 in different months and weather systems is conducted.On this basis, the physical response characteristics of the catalysis process are analyzed through typical cases. The results show that positive effect of seeding experiments under the influence of the low pressure trough in the South China Sea and the South China coast is relatively obvious, and the average absolute precipitation increment of cloud seeded experiments is 2.00 mm higher than that of cloud unseeded experiments. The warm cloud-seeding experiments in July, August, and September all showed different level positive effect of precipitation enhancement. The warm cloud-seeding experiments in August had the highest average absolute increment of precipitation, which is 4.71 mm. For the total warm cloud-seeding experiments of the two sites in Hainan Island, the average absolute precipitation increment is 0.73 mm, the average relative precipitation increase and average water increment is 13.52% and 39.73×104 m3 respectively. From the physical evaluation of typical case, 0.5 h after catalysis is critical moment, after which the gap of almost all physical parameters between seeded cloud and contrast cloud is widened.
