Why does it rain every Qingming Festival?

The Qingming Festival is a traditional festival in China and the most important festival of worship, a day of ancestor worship and tomb-sweeping. Tomb-sweeping is commonly known as visiting the graves, an activity to honor the dead. Most Han Chinese and some ethnic minorities sweep their tombs on Qingming Festival. According to the old custom, when sweeping graves, people should bring wine, food, fruits, paper money and other items to the graveyard, offer the food in front of their loved ones' graves, then burn the paper money, cultivate new soil for the graves, fold a few young green branches and stick them on the graves, then bow and worship, and finally eat the wine and food and go home.

It is believed that everyone has memorized the poem: "The rain falls one after another during the Qingming Festival, and the pedestrians on the road want to break their souls". It tends to rain around Ching Ming, especially in the south, but why does it rain when Ching Ming is clearly a cultural festival? First of all, we need to know how the rain comes. The water in the rivers, lakes and seas evaporates into water vapor that rises high into the air, and the higher up you go, the colder it gets. These water vapors liquefy into small droplets in the cold high air to form clouds, and the small droplets in the clouds collide with each other to become large droplets, which eventually fall down to form rainfall.

So the question is, why does it rain around the time of the Qingming Festival? In fact, Qingming is not just a day for sweeping graves. As one of the 24 solar terms, Qingming itself represents a half-month-long meteorological phase. China's climate has always been governed by two forces, the cold winds from Siberia and the warm winds from the Pacific Ocean. As the sun's point of direct sunlight moves north and south, the forces of these two forces are in opposition to each other.

In the spring, the northern hemisphere receives more sunlight. The Pacific warm winds carry a lot of water vapor with them, so around the time of the Qingming Festival, the water vapor in the Pacific warm winds is liquefied by the cold winds and low temperatures at high altitudes, forming rainfall. That said, it's probably clear. The rainfall in Jiangnan, which stretches over many days during the Qingming season, is caused by the interaction of cold and warm air currents.