The summer solstice is in the middle of summer, that is, noon, which belongs to the sun; Although the summer solstice is full of yang and the longest day, it is not necessarily the hottest day of the year, so the heat near the surface is still being accumulated and has not reached the maximum.
The summer solstice is not only one of the 24 solar terms, but also a festival in the "four seasons and eight festivals" in ancient times. Since ancient times, people have the custom of worshipping gods and ancestors on the summer solstice. In addition, after the summer solstice, people generally eat Qingbuliang soup, herbal tea and sour plum soup to escape the heat.
The summer solstice is the turning point of the sun's northward travel. After the summer solstice, the direct point of the sun began to move south from the Tropic of Cancer, and the days in the northern hemisphere began to shorten gradually.
For China, which is located in the north of the Tropic of Cancer, after the summer solstice, the height of the noon sun began to decrease day by day; For China, which is located in the south of the Tropic of Cancer, the height of the noon sun returns to the south after the summer solstice, and it begins to decrease day by day after the sun shines again.
The historical origin of the summer solstice
"Twenty-four solar terms" is the product of ancient farming civilization. People have discovered the changes of the four seasons in nature, and gradually realized that there are laws to follow in the changes of climate and phenology in a year. Observing the Big Dipper at dusk every day, people find that in different seasons, the orientation of the Big Dipper is different from that of bucket handle.
Therefore, the Big Dipper has long been a star sign indicating the season. For example, "Guanzi Circulation" wrote: "bucket handle refers to the east, and the world is spring; Bucket handle refers to the south, and the world is summer; Bucket handle refers to the west, and the world is autumn; Bucket handle refers to the north, and the world is winter. "
Baidu Encyclopedia-Summer Solstice