Why do you say "it rains in succession during the Qingming Festival"

In fact, there is a scientific explanation for the rainy season.

Qingming is not just a day to sweep graves. As one of the 24 solar terms, Qingming itself represents a meteorological stage that lasts for half a month.

Qingming is 15 days after the vernal equinox. At this time, the direct point of the sun began to move from the equator to the north, and the cold air mass and the warm air mass from the tropical ocean met in Qingming.

When cold and warm air masses meet, usually the cold air mass is below and the warm air mass is above. A cold air mass pushes a warm air mass, which is called a cold front, and vice versa. The two air masses are evenly matched, and neither can live without the other. This is called a quasi-static stop. Every spring, a quasi-static front stays in the middle and lower reaches of the Yangtze River.

The gradient between the two air masses is particularly small, forming a wide cloud and rain area. However, the intensity of precipitation is very small, and most of them belong to the type of intermittent urination.