What month is the tail in winter?

The severe cold day is located at the intersection of longitude 300, 1, 20-2 1.

Winter is one of the four seasons, which traditionally begins with "beginning of winter" among the 24 solar terms. In winter, life is closed and everything enters a state of recuperation. In winter, that is, "everything will be harvested in the end", after beginning of winter, everything began to be hidden. Li Si's division of four seasons reflects many characteristics such as climate and phenology. The four seasons are often divided according to the change of temperature, and the method of "weather average temperature" proposed by modern scholar Zhang Bao _ is adopted. According to the four seasons divided by the weather average temperature method, the average daily temperature is equal to or lower than 10 degrees Celsius for five consecutive days, which is regarded as entering winter.