Why is the probability of rain so high on July 7? I want a scientific explanation!

1. Legend: The seventh day of the seventh lunar month is the day when the cowherd and the weaver girl meet. On this day, countless magpies will fly to the sky and build a magpie bridge to cross the river for the Cowherd and the Weaver Girl. It is said that there will be fewer magpies in the world on Tanabata every year, because they all fly to the sky to build bridges. And after Tanabata, the hair on the magpie's head will fall off, because Tanabata went to bridge the bridge. Some people say it will rain on Tanabata night, which is the tears of joy after the reunion of Cowherd and Weaver Girl.

2. Meteorology: The phenomenon that it often rains on Tanabata should be a climate law. In July, it was rainy in most places, and with the ancient legend, people felt that it would really rain on Tanabata.

It is also believed that the rain on Qixi indicates the harmony between husband and wife and the prosperity of the family. However, meteorologists put it another way, that is, on Tanabata Day, the Jianghuai Valley was generally in a period of cold and warm air confrontation, and it was rainy, so the probability of rain on Tanabata was high.

In addition, many legends are based on some realistic laws, which is why these legends can be circulated for thousands of years. Our ancestors were really great, and the solar terms in our lunar calendar were so in line with the laws of nature. Therefore, the legend about the rain on Qixi Festival is also a summary of the laws of nature by our ancestors.

Happy tanabata! Everything will be all right, jack shall have Jill!