What's the difference between the weather before and after Tomb-Sweeping Day?

Tomb-Sweeping Day, also known as the outing festival, according to the solar calendar, between April 4th and 6th every year, it is the season of beautiful spring and lush vegetation, and it is also a good time for people to have a spring outing (called outing in ancient times), so the ancients had the custom of going for an outing in Qingming and carrying out a series of sports activities. Tomb-Sweeping Day, also known as March Festival in ancient times, has a history of more than 2,000 years. Tomb-Sweeping Day is one of the 24 solar terms around April 5th in the Gregorian calendar. Among the 24 solar terms, Qingming is the only solar term that is both a solar term and a festival.

Although it indicates that the weather is getting warmer and more colorful, it is often "noisy". As early as the Liang Dynasty, it was recorded that there were often "strong winds and even rain" during the Cold Food Festival in Tomb-Sweeping Day two days ago. If it rains on Qingming day, it is called "throwing fire rain", that is, "Qingming rain" Is such a day, Xiao Du (Du Mu, Li Shangyin also called "Du Xiaoli") wrote.

According to modern statistics, the daily precipitation times of some provincial capital cities, Tomb-Sweeping Day 195 1 ~ 1980 and 198 1 ~ 20 10, were analyzed. It is found that after the reform and opening up, the frequency of rain in Tomb-Sweeping Day has decreased. Moreover, the number of precipitation in the south is generally more than that in the north. Especially in the south of the Yangtze River, represented by Changsha and Nanchang, it rained more than 30 times in Tomb-Sweeping Day from 195 1-20 10, which means more than half of Tomb-Sweeping Day has rain.

According to the characteristics of solar terms, the atmosphere of Tomb-Sweeping Day in Tomb-Sweeping Day begins around April 5th and ends around April 20th, that is, the first half of April. Judging from the distribution of precipitation days in the first half of April all the year round, it really proves that the weather in Tomb-Sweeping Day is rainy in the south of the Yangtze River. This feature can also be reflected in the precipitation data along the middle and lower reaches of the Yangtze River and more cities in the south of the Yangtze River.

However, since the beginning of 2 1 century, the Qingming rain has increased again. Especially in Beijing, the precipitation times in Tomb-Sweeping Day from 200 1 to 20 10 are as many as those in Hangzhou, Nanjing and Wuhan. Especially after 20 10, it seems that the rain in Tomb-Sweeping Day is still increasing. From 20 1 1 to 20 14 in Tomb-Sweeping Day, it is not only sunny in the south, but also rainy in many areas in the north.