The origin of the great cold

The origin of the name "Great Cold" is named after Xiaohan and also named after extremely cold weather.

As for the origin of the name of the Great Cold, it is quoted from Li Sanzong's Historical Records A General Examination of Shi Tian. "The Great Cold is moderate, and the upper surface is slightly cold, so it is called the Great Cold, and the cold is extremely negative, so it is called the Great Cold."

In other words, the name of Great Cold comes from two sources: one is named after Little Cold; The second is named after the extremely cold weather. What we can know is that a day with extremely cold weather is called "Great Cold", when the sun reaches 300 degrees of the yellow meridian.

Seasonal characteristics

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 northwest wind flow control and constantly supplemented cold air, China will have a sustained low temperature.

Like slight cold, great cold is also a solar term indicating the degree of cold weather. Modern meteorological observation records show that in some areas of China, severe cold is not as good as slight cold, but in some years and a few coastal areas, the annual minimum temperature will still appear in the severe cold solar terms. Therefore, it is necessary to continue to do a good job in the cold protection of crops, especially to protect livestock from wintering.