What is the coldest solar term?

The coldest time in winter in our country is slight cold and severe cold, which is roughly in January.

Minor Cold

The slight cold value is around Gregorian calendar 1.5. After the slight cold, it began to enter the cold season. When cold air accumulates for a long time, it becomes cold. At this time, the weather is cold but not extreme, so it is called slight cold. The "March 9th" in the middle of winter is basically within this solar term. In meteorological records, it is the coldest weather in a year, and it is said that slight cold is better than severe cold. Because of the low temperature, wheat, fruit trees, stored melons and vegetables and livestock and poultry often suffer from freezing injury. "Slight cold and severe cold are frozen into a ball" and "Walking in the street, losing money" are all ancient folk proverbs describing the cold season. In the agricultural society, at this time, farming has ended and harvesting has been completed, and every household has begun to buy new year's goods and prepare for the New Year. A slight cold solar fog will make the next year's grain harvest abundant. It cleared up after the cold lake, and the west wind was frosty. On the first day of the twelfth lunar month, there was a disaster of six animals in Dongfeng. If there is heavy snow and drought this year, if it is weather, farmers will make a fortune next year.

Major Cold

The great cold is around Gregorian calendar 1.20. At this time, the weather is extremely cold, so it is called great cold. The Great Cold is the last solar term in a year, which is often higher between April 9 and May 9. The average temperature in the Yangtze River basin in China is -2-4℃, the lowest temperature is generally-14~ 17℃, and the extreme minimum temperature can be reduced to -20℃. The maximum frozen soil depth is 30~40 cm, which is the deepest solar term of frozen soil in the whole year. In some years, the annual minimum temperature will appear in this solar term.