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 southern China, there are customs of offering sacrifices to ancestors and enjoying the winter solstice. In northern China, it is a custom to eat jiaozi from winter to Sunday every year.

Meteorological changes:

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, and the real cold winter is after the winter solstice. Due to the disparity of climate in different parts of China, this astronomical climate feature is obviously late for most parts of China.