Winter solstice, also known as solstice, winter festival, child year, etc. It has both natural and humanistic connotations. It is not only an important solar term among the 24 solar terms, but also a traditional folk ancestor worship festival in China. The solstice in winter is one of the eight festivals in four seasons, and it is considered as a big holiday in winter. In ancient times, there was a saying that the winter solstice was as big as a year. The custom of winter solstice varies in content or details due to different regions. In the south of China, there is a custom of ancestor worship. In northern China, it is a custom to eat jiaozi from winter to Sunday every year.

The winter solstice is the 22nd solar term in the "24 solar terms", and the solar calendar reaches 270 degrees. Every year, the festival is held on 65438+February 2 1-23 in the Gregorian calendar. The solstice in winter is the extreme point of direct sunlight spreading to the south. From winter to the sun, the sun shines directly on the Tropic of Capricorn, and the sun is most inclined to the northern hemisphere, and the solar altitude angle is the smallest. In all parts of the northern hemisphere, the days are the shortest and the nights are the longest.

Meteorological change

From winter to the future, although the solar altitude angle gradually increases, it is a slow recovery process, and the heat lost every day is still greater than the heat received, showing a situation of "making ends meet". On the day of "March 9 and April 9", the accumulated heat is the least, the temperature is the lowest, and the weather is getting colder and colder. China has a vast territory, and the climate and landforms vary greatly from place to place. Although the days from winter solstice are short, the temperature from winter solstice is not the lowest; It won't be very cold before the winter solstice, because there is still accumulated heat on the surface. The real cold winter is after the winter solstice.

Because of the great difference in climate in China, the astronomical climate characteristics are obviously late for most parts of China. After the winter solstice, the climate in all parts of China will enter the coldest stage, which is often called "September Cold" and "September Cold".