Seasonal variation law of the length of day and night

Latitude variation law of the length of day and night: the day is long in the hemisphere with direct sunlight, and the night is short. The longer the day is in high latitudes, the extreme day phenomenon appears in areas with latitude higher than a certain latitude (90-the latitude with direct sunlight); The hemisphere that is not directly illuminated by the sun has shorter days and longer nights. The higher the latitude, the longer the night. The phenomenon of extreme night occurs in areas where the latitude is higher than a certain latitude (90-the latitude where the direct point of the sun is located).

Seasonal variation law of the length of day and night: If the direct point of the sun moves northward, the days in the northern hemisphere will become longer and the nights will become shorter, and the number of regions with extreme night phenomena in the Arctic Circle will decrease (65438+February 22nd to March 2nd1) or increase (March 2nd1~ June 22nd); If the direct point of the sun moves south, the days in the northern hemisphere will be shorter and the nights will be longer, and the areas with extreme daytime phenomena in the Arctic Circle will decrease (June 22 ~ September 23) or the areas with extreme night phenomena will increase (September 23 ~ 65438+February 22). The southern hemisphere is the opposite. The vernal equinox and autumnal equinox divide the world equally into day and night. The equator is equally divided day and night throughout the year.