The main characteristics of the general atmospheric circulation in April 2015 were as follows. The circulation of polar vortex in the Northern Hemisphere was in a dipole type, with one center located between the west of Greenland and Canada, and the other in the northeast of Asian. The strength of both centers was 4-8 dagpm lower than normal years, but the Ural Mountain ridge was 8-12 dagpm higher than normal. The Northwest Pacific subtropical high extended to west more than usual with larger area. The location and strength of south branch trough was close to normal annual means. The monthly mean temperature was 11.6℃, being 0.6℃ higher than normal. The monthly mean precipitation was 43 mm, which is close to the annual average (44.7 mm). While the precipitation in the region to the north of Yangtze River was more than average, the situation in South China was opposite. Severe convective weather events occurred frequently in April, with large scope of hail, thunderstorm and gust seen in 1-4, 19-20, and 28-29. Two sandstorms happened in the northern part of China.