What is the standard for entering winter?

There are two opinions about China's winter standards. One is astronomical, that is, beginning of winter solar terms enter winter after their arrival, while beginning of winter solar terms really mean the beginning of winter. The other is divided according to the climate. If winter is defined from the climate, the time of winter in different regions of China will be different.

Winter in the first case: winter in astronomy.

Astronomically speaking, winter is the solar term in beginning of winter. However, the winter weather in early winter really lags behind. At this time, in addition to signs of winter in some parts of the north, many places in the south are still autumn scenery, where the temperature is neither high nor low, and it is refreshing and comfortable. If you insist that this scene is winter, it is a bit unreasonable.

As far as the coastal areas of South China are concerned, beginning of winter is still crisp in autumn and even a little hot. This "winter" is different from that. On the contrary, in the northeast and northwest, it is already a snowy scene, which naturally belongs to winter. So in order to meet the actual situation, we have a second winter standard.

The second situation is winter: winter in climate.

Climatic winter is defined as reaching a certain temperature standard, that is, the average temperature is lower than 10℃ for five consecutive days. However, at the beginning of winter, many areas did not reach this standard, so the winter on this day was not a real winter.

According to this standard, the area north of Huaihe River in Qinling Mountains in China generally reached the standard in 1 1 and 65438+February, and some areas south of Huaihe River in Qinling Mountains also reached the standard, but less. Not to mention Hainan and Guangdong, it is absolutely impossible for beginning of winter to have this standard. Even most areas have entered winter, and there is no sign of winter here. Otherwise, how can we say that Hainan has four seasons like spring?