Great cold is the last of the 24 solar terms in the whole year. Every year around 65438+1October 20th in Gregorian calendar, when the sun reaches 300, it is a severe cold. Twenty-four solar terms: "In mid-December, I met before (slight cold)." "Judge the time" is quoted from "Three Rites and Righteousness": "Great cold is the middle, and the upper form is slight cold, so it is called the extreme of great cold, so it is called great cold." At this time, the cold wave frequently goes south, which is the coldest period of the year in some parts of China. The wind is strong, the temperature is low, and the snow on the ground does not melt, showing a cold scene of ice and snow.