What happened in winter?

People wear too many clothes in winter; The climate also began to get cold; Animals begin to enter the winter sleep period; Almost all trees have only bare branches; The nights are long and the days are short in winter.

Traditionally, the twenty-four solar terms "beginning of winter" are regarded as beginning of winter. 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. At present, four seasons are often divided according to the temperature change, and the method of "weather average temperature" proposed by modern scholar Zhang Baokun 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.

Extended data:

In winter in the north, affected by the cold high pressure in Mongolia and Siberia, cold air often forms a cold wave southward, which greatly reduces the temperature. The south is affected by the warm and humid air flow from the ocean, and the winter is mostly mild. This is caused by the climate.

East-west mountains, such as the Qinling Mountains, block the cold air mass from going south, making the temperature high in the south and low in the north, so the temperature difference is naturally large. This is due to the terrain.

Under the comprehensive effect of many geographical factors (solar radiation, climate and topography), the temperature difference between north and south in China is much larger in winter than in summer.