What does the vernal equinox mean?

The vernal equinox is the midpoint of 90 days in spring. One of the 24 solar terms, around March 20 of the Gregorian calendar every year, when the sun is located at 0 (vernal equinox) of the yellow meridian. On the vernal equinox, the sun shines directly at the equator of the earth, and the seasons in the northern and southern hemispheres are opposite. The northern hemisphere is the vernal equinox and the southern hemisphere is the autumnal equinox. The vernal equinox is a new year in Iran, Turkey, Afghanistan, Uzbekistan and other countries, with a history of 3,000 years.

During the vernal equinox, the daily average temperature in all parts of China rose steadily to above 0℃ except the alpine mountain area and the area north of 45 north latitude. At this time, the cold has passed and the temperature has risen rapidly, especially in North China and Huanghuai Plain. The daily average temperature rises to above 10℃ almost at the same time as the rainy areas along the Yangtze River and the south of the Yangtze River, entering a bright spring.

On the vast land, on the bank of willow green, the grass grows in Fei Ying, the wheat is jointing, the rape blossoms are fragrant, the peach blossoms are red, and Li Bai is coming in spring. South China is a scene of late spring. According to the climate law, the precipitation in Jiangnan increased rapidly at this time, and it entered the period of "peach blossom flooding" in spring; In the northeast, north and northwest regions where "spring rain is as expensive as oil", precipitation is still very little, so resisting the threat of spring drought is the main problem of agricultural production.