What is the day before the great cold?
The Great Cold is the last of the 24 solar terms, and it is called "Great Cold" when the sun reaches 300 degrees on June 20 ~ 265 and 438+0 of the Gregorian calendar every year. Li Sanzong's Yi's Shi Shi Tong Kao Shi Tian was quoted to explain: "Great cold is the middle, and the upper form is slight cold, so it is called great cold, and cold is the antipode, so it is called great cold", which is extremely cold. During this festival on March 9th and April 9th, the cold wave frequently goes south, which is the coldest season of the year and the period with the least rainfall.
The great cold comes at the end of the year, winter goes to spring, and after the great cold, a new cycle begins. In some parts of China, during the period from the Great Cold to beginning of spring, there were many important folk customs, such as taking off old cloth to make bacon, offering sacrifices to stoves and ending sumptuous food. Tail luxury food is also called "tooth-making" and "luxury food". There is a folk custom of "eating tail teeth" after eating luxury food, and the popular "annual meeting" at the end of the year is the legacy of "tail luxury food".
Meteorological change
During the severe cold solar term, the atmospheric circulation is relatively stable, and the adjustment period of circulation is about 20 days. When this circulation is adjusted, there will often be a wide range of rain and snow weather and strong winds to cool down. When the west of 80 degrees east longitude is a long wave ridge and East Asia is a coastal trough, under the influence of the northwest wind and the constantly supplemented cold air, China will have a sustained low temperature. In some parts of China, severe cold is not as cold as slight cold, but in the southern coastal areas of China, the lowest temperature in a year appears in the severe cold solar terms.
Great cold and slight cold are solar terms indicating the cold weather. According to the statistics of perennial climate data in China, the coldest period of a year in northern China is in the middle of June 65438+ 10 (June1-20) of the Gregorian calendar every year. The annual slight cold solar term starts from 65438+1October 5~7, and one solar term is about 15 days, and the middle section is just within the slight cold solar term. So for most parts of the north, slight cold is indeed colder than severe cold.
Baidu Encyclopedia-Great Cold