The main characteristics of the general atmospheric circulation in January 2024 are as follows.There were two polar vortex centers in the Northern Hemisphere.The Eurasian mid-and high-latitude cir-culation showed a two-trough-one-ridge pattern.The East Asian trough was more eastward.The monthly mean precipitation(16.3 mm)over China was 15.6%more than normal(14.1 mm).The monthly average temperature was-3.8 ℃,which was 1.0℃ higher than that in the same period of normal years.Cold and warm temperatures fluctuated greatly during the month.There was one nationwide cold wave process and two widespread persistent fog-haze weather processes,among which the cold wave weather process from 20 to 22 January presented the characteristics of a wide range of influence,and cooling,long duration of strong wind and heavy snowstorm.