What is the standard for entering winter?

In climatology, the standard of entering winter is defined as reaching a certain temperature standard, and the average temperature is lower than 10℃ for five consecutive days.

Winter is one of the four seasons, between autumn and spring. Astronomically speaking, it was from February to March in 65438. China used to refer to the three months from beginning of winter to beginning of spring, and also referred to the "October, November (winter) and December (wax) months" of the lunar calendar. The time in the northern and southern hemispheres is different.

According to the meteorological significance, in the temperate and cold regions of the southern hemisphere, the winters are in June, July and August (or from May 2/kloc-0 to August 22 according to the constellation standard), and in the temperate and cold regions of the northern hemisphere, the winters are in 12, 1 and February (or according to the constellation standard 16544)

Extended data:

Climatic characteristics:

In northern China, snow is an important symbol of winter. In the middle and lower reaches of the Yellow River in northern China and its vicinity, the snow in winter is often not as big as the light snow solar terms. The main reason is that the light snow solar term is ahead, the temperature is high, the total amount of water vapor in the air is larger than that of heavy snow solar term, and the possibility of heavy snow is greater.

In fact, the solar term with the heaviest snow in the middle and lower reaches of the Yellow River and its vicinity is neither "light snow and heavy snow" nor "slight cold and severe cold" (because the temperature was low at that time and there was less water vapor in the atmosphere), but a rainy solar term in spring.