Abstract:The main characteristics of the general atmospheric circulation in January 2017 are as follows. There was one polar vortex center in the Northern Hemisphere with the stronger strength than normal year. The circulation presented the trough ridge trough pattern in middle high latitudes. The south branch was as strong as normal, located near the west of 90°E averagely. The subtropical high also had the same strength as usual. In addition, the monthly mean precipitation is 12.4 mm, 6% less than normal and mean temperature is -3.4℃, 1.6℃ higher than normal (-5.0℃), which is the third high value for the corresponding period since 1961. There were two cold air processes, two major rainfall processes and two large scale fog haze weather processes during this month. Among them the fog haze event from 30 December 2016 to 6 January 2017 was characterized by the most extensive, the longest and the most intensive fog haze weather in January.