The following are the main characteristics of the general circulation of atmosphere in October 2011. There were two polar vortex centers in the Northern Hemisphere. The circulation presents a fourwave pattern in middle-high latitudes. The intensity of the center of Atlantic and the east of Pacific deep trough is stronger than that of troughs in average conditions. The average temperature (10.6℃) is 1.0℃ higher than and the average precipitation (38.7 mm) is 1.7 mm more than compared the same time of normal years during October in 2011. There were four precipitation processes, two cold air processes and three heavy fog processes in the month.