Abstract:Statistical analysis of flash heavy rain in Jiangxi warm season from 2010 to 2016 is conducted based on hourly precipitation data from 1597 automatic weather stations. The precipitation field is divided into five regions by REOF: south part of northern Jiangxi (Region Ⅰ), Fuzhou and central Ganzhou (Region Ⅱ), northern Jiangxi (Region Ⅲ), southern and northern Ganzhou (Region Ⅳ), and western of central Jiangxi (Region Ⅴ). The high frequency areas of flash heavy rain are mainly distributed near mountains and river valleys. They are the eastern side of the Luoxiao Mountain, the western foot of Wuyi Mountain, the Xinjiang, the Le’an and the Changjiang River valleys. The frequency of flash heavy rain near the river valley is the highest in the Changjiang River valley (16.9 times one year), the highest near the mountains is the east side of the Luoxiao Mountain (12.6 times one year). The extreme flash heavy rain areas are located in the mountain areas of Northeast Shangrao (3.7 times one year) and the Jinjiang River valley (3.3 times one year). Flash heavy rain mainly occurred in the 3rd pentad of May, middle of June and July, and from 2nd to 3rd pentads of August. The diurnal variation characteristics of Regions Ⅳ and Ⅴ are single peak types, diurnal variation characteristics of Regions Ⅰ, Ⅱ and Ⅲ are bimodal patterns. The main peaks are concentrated at 17:00 BT in the afternoon; the second peak is during 08:00-10:00 BT in the morning. The contribution rate of flash heavy rain to rainstorm is basically above 40%, nearly half of the rainstorm weather processes in Regions Ⅰ and Ⅱ are contributed by flash heavy rain. The Xinjiang River valley is the center of rainstorm rainfall, but not the center of flash heavy rain rainfall. However, the Changjiang River valley and the western foot of Wuyi Mountain are both the centers of rainstorm rainfall and the flash heavy rain rainfall.