Solar term reversal

"When it thunders in summer, Huangmei turns upside down" means that after the rainy season, if it thunders in summer, the rainy season will turn upside down again, which is called "inverted Huangmei".

On the eve of the summer heat, it is the day with the highest temperature, the longest sunshine time and the strongest sunshine radiation in a year, so every household will choose this day to "bask in the sun", that is, hang the clothes stored in the cupboard outside to be exposed to the sun to prevent moisture, moisture, mildew and moth.

Causes of Meiyu season

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.

Typical plum rains generally "enter plum blossoms" in the middle and late June, and bloom in early to mid-July. Meiyu refers to the rainy days before plum blossom, which generally starts in mid-April and lasts for about half a month.