Abstract:The main characteristics of the general atmospheric circulation at 500 hPa in April 2023 are as follows. There were two polar vortex centers in the Northern Hemisphere, stronger than usual. The circulation in middle-high latitudes showed an anomalous four-wave pattern, and the Asian circulation was relatively flat and straight. The northern part of China had a negative anomaly in the geopotential height field, the strength of western Pacific subtropical high was weaker than that in normal years, and the south branch was a little weaker, more westward than usual. The monthly mean temperature was 11.4℃, 0.1℃ lower than normal. The monthly mean precipitation was 48.7 mm, 11.7% more than the value (43.6 mm) in normal periods, of which the precipitation in the Northwest China and North China was significantly more than that in normal years. In addition, cold air was very active during this month, and four cold air processes occurred, bringing large amplitude of drop in temperature. There were four large-scale torrential rain processes across China and six regional severe convection processes with strong local intensities. In addition, six sand-dust events occurred in northern China, and drought maintained and developed in Yunnan and other places.