The main characteristics of the general atmospheric circulation in January 2023 are as follows. There were two polar vortex centers in the Northern Hemisphere. The Northeast Asia low vortex was stronger. The East Asian major trough was more eastward than normal, and the south branch trough was weaker. Meanwhile, the monthly mean precipitation over China was 8.8 mm, which is 38% less than normal (14.3 mm). The monthly mean temperature was -4.4℃, 0.4℃ higher than normal (-4.8℃). There were three cold air processes in the middle and late of the month, and the temperature changed from abnormally warm in the early 10 days to generally cold in the late 10 days. In addition, extremely cold weather appeared in Heilongjiang Province with the lowest temperature in Mohe declining to as low as -53℃, setting a new record of the lowest temperature in China. From 13 to 16 January, the first largescale cold wave of this year occurred, characterised by severe cooling, strong winds and wide range of rain and snow. Xinjiang, Shaanxi, Shanxi, Henan and other provinces experienced heavy snow or blizzard. Besides, the first dust weather affected northern China, and in the first dekad, the atmospheric diffusion and wet clearance conditions were not good so that persistent haze weather stayed for days.