What months are spring, summer, autumn and winter?

According to the meteorological classification method, in the meteorological department, March to May is usually spring, June to August is summer, September to 165438+ 10 is autumn, and 12 is winter. Refers to the four seasons of the earth in a year, which is the result of the earth's orbit around the sun.

Our earth revolves around the sun and rotates around its own axis, but the axis is not perpendicular to the orbital plane, but has an inclination of 23 degrees and 27 minutes. It is precisely because of this tilt that the direct point of the sun on the earth's surface moves between the Tropic of Cancer and the Tropic of Capricorn, thus forming four seasons: spring, summer, autumn and winter.

Extended data:

Change rules

From vernal equinox to summer solstice to autumnal equinox, the northern hemisphere is in summer and the southern hemisphere is in winter. During this period, the northern hemisphere has long days and short nights, while the southern hemisphere has short days and long nights. The north pole is in the extreme day and the south pole is in the extreme night; The height of the sun north of the Tropic of Cancer is always greater than the average, while the height of the sun south of the Tropic of Cancer is less than the average.

North of the Tropic of Cancer, the sun rises on the northeast horizon and sets on the northwest horizon. On the vernal equinox, the sun all over the world rises in the east and sets in the west.

From the autumnal equinox to the winter solstice and then to the vernal equinox, the northern hemisphere is in the winter half year and the southern hemisphere is in the summer half year. During this period, the length of day and night, the extreme value of day and night and the height of the sun in the northern and southern hemispheres are contrary to the above situation. North of the Tropic of Cancer, the sun rises from the horizon in the southeast and sets on the horizon in the southwest.

From summer solstice to winter solstice, from summer to winter in the northern hemisphere and from winter to summer in the southern hemisphere. During this period, the days in the northern hemisphere are getting shorter and shorter, the nights are getting longer and longer, and the extreme day area is getting smaller and smaller. In the southern hemisphere, the days are getting longer and longer, the nights are getting shorter and shorter, and the polar night zone is getting smaller and smaller. The height of the sun has been declining in the north of the Tropic of Cancer and rising in the south.

North of the Tropic of Cancer, the rising direction of the sun changes from northeast to southeast, and the setting direction changes from northwest to southwest. The autumnal equinox rises due east and lands due west.

From the solstice of winter to the solstice of summer, from winter to summer in the northern hemisphere and from summer to winter in the southern hemisphere. The changes of the length of day and night, the extreme value of day and night, and the height of the sun in the northern and southern hemispheres are contrary to the above situation. North of the Tropic of Cancer, the rising direction of the sun changes from southeast to northeast, and the setting direction changes from southwest to northwest.

From the winter solstice to the vernal equinox, from the summer solstice to the autumnal equinox, the number of days around the world is close to the average (12 hour), and the range of extreme days and nights is gradually shrinking. The height of the sun north of the Tropic of Cancer and south of the Tropic of Capricorn is close to the average. North of the Tropic of Cancer, the rising direction of the sun gradually approaches due east, and the setting direction approaches due west.

From vernal equinox to summer solstice, from autumnal equinox to winter solstice, the length of day and night around the world is changing to an extreme value, and the range of extreme day and night is gradually expanding. The height of the sun north of the Tropic of Cancer and south of the Tropic of Capricorn also tends to be extreme. North of the Tropic of Cancer, the rising and setting directions of the sun move to the northeast, southeast, northwest and southwest respectively.

Baidu encyclopedia-four seasons