Abstract:The main characteristics of the general atmospheric circulation in April 2021 are as follows. The 500 hPa geopotential height presented a three wave pattern in the high latitude of Northern Hemisphere. There was one polar vortex center in the Northern Hemisphere, stronger than usual. The strength of Western Pacific subtropical high was weaker than that in normal years, but the south branch trough was stronger than usual. The monthly mean temperature was 11.1℃, 0.1℃ higher than normal. The monthly mean precipitation over China was 42.5 mm, which is 5.8% less than normal. However, the mean precipitation in Qinghai Province this month was recorded the most for the same period of history. Four nationwide strong cold air processes happened this month. The drought conditions in Southwest China and eastern part of South China persisted or worsened. Two sand dust events occurred across the northern part of China. Several provinces were attacked by severe thunder storms and hail, and some areas were hit harder.