When did winter begin in the southern hemisphere?

Summer in the southern hemisphere is 65438+February to February, and winter is June to August, which is contrary to the four seasons in the northern hemisphere. That is to say, from 9.23 to 12.22 in spring, from 12.22 to 3.2 1 in summer, from 3.2 1 to 6.22 in autumn and from 6.22 to 9.23 in winter.

The seasonal division method divides a year into four seasons according to the astronomical height of the sun and the length of day and night. Therefore, summer is the season with the highest sun height and the longest day, and winter is the season with the lowest sun height and the shortest day.

Spring and autumn are the transitional seasons of winter and summer. There are different standards about the specific methods of dividing the four seasons. In ancient China, beginning of spring (February 4th), Changxia (May 6th), beginning of autumn (August 8th) and beginning of winter (165438+1October 8th) were the four seasons, and the vernal equinox, summer solstice, autumnal equinox and winter solstice were regarded as spring and summer respectively.

This division of four seasons is not consistent with the actual climate change in various places. For example, beginning of spring is the beginning of spring, but in some places, it is the middle of winter; Beginning of autumn is the beginning of autumn, and some places are hot in summer.

Extended data:

Seasonal division method:

1, astronomical division

From the astronomical phenomenon, the change of four seasons is the seasonal change of the length of day and night and the height of the sun. In a year, the season with the longest day and the highest sun height is summer, the season with the shortest day and the lowest sun height is winter, and the transitional season between winter and summer is spring and autumn.

Therefore, the astronomical division of the four seasons is based on the vernal equinox (March 2 1), summer solstice (June 2 1), autumn equinox (September 2 1) and winter solstice (February 2 1). Namely: spring from the vernal equinox to the summer solstice, summer from the summer solstice to autumn, autumn from the autumn equinox to the winter solstice, and winter from the winter solstice to spring.

2. Meteorological zoning method

In the meteorological department, March-May is usually spring, June-August is summer, September-1 65438+10 is autumn, February-February of the following year is winter, and1,April, July and10 are often winter.

3. Ancient division

Take beginning of spring (February 4th or 5th) as beginning of spring, Changxia (May 5th or 6th) as long summer, beginning of autumn (August 7th or 8th) as beginning of autumn and beginning of winter (165438+1October 8th or 9th) as beginning of winter.

4, the lunar calendar division method

In our country, it is customary to divide the four seasons by lunar month. Lunar calendar1~ March is spring, April-June is summer, July-September is autumn, and 10 ~ 12 is 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, waiting for the temperature division method

This division is based on waiting time (five days is a waiting time). Take the average temperature as the temperature index to divide the four seasons. Summer begins when the average climate temperature is stable above 22℃, winter begins when the average climate temperature is stable below 10℃, and spring and autumn begins when the average climate temperature is between 10 ~ 22℃. 10℃ to 22℃ is spring, and 22℃ to 10℃ is autumn.

Baidu encyclopedia-seasonal division method

Baidu encyclopedia-transitional season