Abstract:The main characteristics of the general atmospheric circulation in October 2018 are as follows. Over the Northern Hemisphere, the polar vortex showed a dipole pattern. The circulation presented a four wave pattern in middle high latitudes. The western Pacific subtropical high extented remarkably more westward than normal. The monthly mean precipitation amount was 28.1 mm, which is 21.6% less than normal (35.8 mm). The monthly mean temperature was 9.9℃, 0.4℃ lower than normal (10.3℃), ran king the lowest since 2002. There was no large range heavy rainfall processes over China. There were five cold air processes, more than usual, and two fog and haze events in the region of Beijing Tianjin Hebei, which were also weaker than usual. There was no landfall typhoon in October 2018.