What is the origin of summer solar terms?

Slight summer heat is the eleventh solar term among the twenty-four solar terms of the lunar calendar, and it is also the fifth solar term in summer, indicating the official start of the last month of summer; On July 7th or 8th every year, when the sun reaches longitude 105, it is a summer solar term. "Twenty-four solar terms": "June Festival" ... It is also hot in summer, and it is small at the beginning of the month, big in the month, and still small today. "Summer heat" means heat, which means slight heat. The ancients thought that the summer heat period was not the hottest time of the year, so it was called summer heat.

In ancient China, the summer heat was divided into three periods: "First, it was warm and windy; Second, wait for crickets to live in space; The third waiting eagle began to crow. " In summer, there is no cool wind on the earth, and all the winds carry heat waves; The words describing crickets in the Book of Songs in July are "Wild July, August, September at home, October in bed." August mentioned in this paper is June in the summer calendar, which is a short time in summer. Because of the heat, crickets leave the field and go to the corner of the yard to escape the heat. In this solar term, the eagle is in the cool high air movement, because the ground temperature is too high.

Around the summer, the western part of South China enters the season with the most rainstorm, and the number of rainstorm days in July and August can account for more than 75% of the whole year, usually about 3 days. Mountain torrents often occur in places with large relief, and even cause mudslides. However, in the eastern part of South China, due to the frequent control of subtropical high, the weather is sunny and hot, and after experiencing a slight summer heat, it began to enter the summer drought period. The climatic characteristics of drought in the east and waterlogging in the west in most parts of southern China have a great relationship with agricultural abundance and waterlogging, so we must take measures to ensure the harvest of drought and waterlogging as soon as possible to minimize the harm.