Abstract:The main characteristics of the general atmospheric circulation in May 2016 were as follows： The circulation of polar vortex in the Northern Hemisphere was in a dipole pattern. The 500 hPa geopotential height presented the distribution of a four wave pattern in the mid high latitude of the Northern Hemisphere. The subtropical high of Northwest Pacific extended to more westward than usual with larger area, almost circling the globe. The monthly mean temperature was 16.3℃, being 0.1℃ higher than normal. The monthly mean precipitation amount was 82.8 mm, 19.1% more than the usual average (69.5 mm). The main weather characteristics in this month were that the onset of South China Sea summer monsoon happened in the last dekad of May; torrential rainfalls were seen frequently in the east of Southwestern China, the south of Southern China and South Yangtze River; and severe convective weather happened widely with greater intensities and severe thunderstorms and hail disaster.