How are the seasons divided in China?

1. Astronomical division method

From the astronomical phenomenon, the four seasons is the length of day and night and the sun's altitude of the seasonal changes. In a year, the season with the longest day and the highest solar altitude is summer, the season with the shortest day and the lowest solar altitude is winter, and the transition between winter and summer is spring and fall. For this reason, the astronomical division of the four seasons method, that is, the spring equinox (March 21), the summer solstice (June 21), the autumn equinox (September 21), the winter solstice (December 21) as the beginning of the four seasons. That is: spring equinox to summer solstice is spring, summer solstice to autumn equinox is summer, autumn equinox to winter solstice is autumn, and winter solstice to spring equinox is winter.

2. Meteorological division

In the meteorological department, usually in the solar calendar March to May for the spring, June to August for the summer, September to November for the fall, December to the next year in February for the winter, and often January, April, July, October as the winter, spring, summer and fall as the representative of the month.

3. Ancient divisions

The beginning of spring (February 4 or 5) as the beginning of spring, the beginning of summer (May 5 or 6) as the beginning of summer, the beginning of autumn (August 7 or 8) as the beginning of autumn, and the beginning of winter (November 8 or 9) as the beginning of winter.

4. Lunar calendar division

China's folk custom to use the lunar month to divide the four seasons. January to March of the lunar calendar for spring, April to June for summer, July to September for fall, October to December for winter. The first day of the first month is the first day of the year and the first day of spring, so it is also called the Spring Festival.

5. Temperature division method

The above four seasons of the method, more suitable for the four seasons of the temperate regions. 1934 Chinese scholar Zhang Baokun combination of climate phenomena and agricultural production, put forward another method of seasonal division. He to wait (every five days for a wait) the average temperature stabilized lower than 10 ℃ as the beginning of winter, stabilized rise to 22 ℃ or more as the beginning of summer. Spring begins when the average temperature rises steadily from below 10℃ to above 10℃. When the temperature steadily decreases from above 22℃ to below 22℃, it is the beginning of fall.

That is: the average temperature ≤ 10 ℃ for the winter, 10 ~ 22 ℃ for the spring, ≥ 22 ℃ for the summer, 22 ~ 10 ℃ for the fall of this method of seasonal division, can be combined with the specific climate and agriculture, so it is more often used.