Astronomical division, with vernal equinox, summer solstice, autumn equinox and winter solstice as the beginning of the four seasons;

2. Meteorological zoning method

March to May is spring, June to August is summer, September to165438+1October is autumn, and 65438+February to February is winter.

3. Division of solar terms

Beginning of spring, Changchun, beginning of autumn and beginning of winter are four seasons.

The climate season division index is based on the waiting temperature method proposed by Mr. Zhang Baokun in 1934, and it is still used in meteorological operations. In ancient China, five days was called waiting period, and waiting temperature was the average temperature of five days. However, in the division of climate seasons, it is not a fixed five days, but a five-day moving average, that is, the average value is calculated by taking the current day and the first four days as a group.

Extended data:

According to the climate season, the daily average temperature or moving average temperature is greater than or equal to 10℃ and less than 22℃ in spring, greater than or equal to 22℃ in summer, less than or equal to 10℃ in autumn and less than 10℃ in winter.

The so-called four seasons are spring, summer, autumn and winter in mid-latitude areas. The difference between spring, summer, autumn and winter is mainly reflected in the amount of solar energy received by the ground, which depends on the angle of sunlight. The same beam of light shines obliquely on the ground and gets less heat per unit area than directly on the ground.

The greater the altitude angle of the sun, the closer it is to direct light, and the more heat it gets per unit area of the ground. Therefore, the division of four seasons is mainly influenced by the change of sun height at noon.

On the solstice of summer, the sun shines directly on the Tropic of Cancer. On this day, the southern hemisphere gets the most solar heat per unit area, and the southern hemisphere gets the least solar heat per unit area. On the solstice of winter, the sun shines directly on the tropic of Capricorn. On this day, the southern hemisphere gets the most solar heat per unit area, while the northern hemisphere gets the opposite.

At the vernal equinox and the autumnal equinox, the sun shines directly on the equator, and the sunlight and heat obtained by each place are roughly equal. So in the west, the four seasons are divided into vernal equinox, summer solstice, autumn equinox and winter solstice; In China, beginning of spring, Changchun, beginning of autumn and beginning of winter are traditionally used to divide the four seasons. These two methods belong to the method of astronomical division of four seasons.

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