When is the rainy season in Shanghai?

The rainy season in Shanghai is usually from mid-June to early July in the solar calendar every year.

The typical plum rain in Shanghai generally "blooms" from early June to mid-June, and blooms from early July to mid-July. Meiyu refers to the rainy days before plum blossom, which generally starts in mid-June and lasts for about half a month.

In China's almanac, it is recorded that plum rains began and lasted all day: the first day was called "entering plum blossoms" and the last day was called "leaving plum blossoms". On the first day after the awn was planted, it entered the plum blossom, which was the first plum blossom before sunrise in shallow Xia Hou.

The total time of plum blossom is between June 6th and 15, and the total time of plum blossom is between July 8th and 19. There is an obvious rainy season in eastern China, with a long rainy period and relatively concentrated rainfall, which is caused by the displacement of the main rain belt from east to west to north, and is a unique phenomenon of the turning point of the atmospheric circulation in East Asia at the turn of spring and summer.

cause

Every year from late April to early May, cold air from the north and warm air from the south meet in South China, forming a quasi-static front in South China. By the end of May, the influence of warm air was strengthened, and the quasi-static front moved northward to Jianghuai area, becoming the quasi-static front of Jianghuai (also known as Meiyu front).

Because the warm air from the south carries a lot of water vapor, when it meets the cold air mass, it will produce a lot of convection activities. Because of the equal influence of cold and warm air during this period, the front stays in Jianghuai area.