Abstract:The main characteristics of the general atmospheric circulation in May 2018 are as follows. Two polar vortex centers were in the Northern Hemisphere and stronger than usual. The circulation at middle high latitudes of the Eurasian showed a three wave pattern, and the degree of meridionality was lower than normal. The strength of Western Pacific subtropical high was stronger than the climatological normal, and the Bay of Bengal trough is slightly weaker than normal. The monthly mean temperature was 17.1℃, higher than normal (16.2℃) by 0.9℃. The monthly mean precipitation amount was 73.1 mm, more than normal by 5.2%. Seven severe rainfall events occurred in southern China this month, and several provinces were attacked by severe thunderstorms and hail disaster. In addition, severe droughts took place in the Northeast China, which was weakened in the later part of month. High temperature weather began to persist in southern China from the middle of May, and two dust weather events happened in northern China.