Abstract:The main characteristics of the general atmospheric circulation in March 2020 are as follows. One polar vortex center was located towards Asia and stronger than usual. The circulation at middle-high latitudes of the Eurasia showed a three-wave pattern, and the East Asian trough was shallow. The Western Pacific subtropical high was stronger than the climatological normal, while the Bay of Bengal trough was equal to usual. Cold airs that affected China were generally frequent but not strong, causing a significant warming in most areas in March. The monthly mean temperature was 6.1℃, higher than normal (4.1℃) by 2℃, and the highest temperature observed at 58 stations broke the historical extreme values. In addition, weak cold air frequently penetrated southwards and cooperated with the activities of the Bay of Bengal trough, resulting in continuous rainy weather in southern China. The monthly mean precipitation amount across China was 35.0 mm, more than the normal by 18.4%. Three nationwide strong cold air processes happened in this month. Under the warmer background in the previous period, 91 stations experienced daily extreme drops in temperature. There were seven rainfall processes in the southern region, three of which were accompanied by obvious severe convective weather. Several provinces were attacked by severe thunderstorms and hail disaster. In addition, four sand-dust weather events occurred in northern China, while severe droughts were found in the east of Sichuan, southern Shaanxi and Yunnan provinces.