What does the vernal equinox mean?

The vernal equinox is the midpoint of the ninety days of spring. One of the twenty-four solar terms, it is around March 20 every year in the Gregorian calendar, when the sun is at 0° of ecliptic longitude (the vernal equinox). On the vernal equinox, the sun shines directly on the earth's equator, 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 Spring Equinox is the New Year in Iran, Turkey, Afghanistan, Uzbekistan and other countries, and has a history of 3,000 years.

During the vernal equinox, except for alpine mountainous areas where winter lasts all year round and areas north of 45° north latitude, the daily average temperature in all parts of China rises steadily above 0°C. At this time, the severe cold has passed, and the temperature has risen rapidly, especially in North China and the Huanghuai Plain. The daily average temperature has risen above 10℃ almost at the same time as the rainy areas south of the Yangtze River and entered the bright spring.

On the vast land, the banks are green with willows, warblers are flying, grass is growing, wheat is jointing, rapeseed flowers are fragrant, peach blossoms are red, plums are white and spring is yellow, and South China is a scene of late spring. From the perspective of climate rules, precipitation in the south of the Yangtze River increases rapidly at this time, entering the spring "peach blossom flood" period; in the vast areas of Northeast, North China and Northwest China, where "spring rain is as expensive as oil", precipitation is still very little, and the threat of spring drought is in agricultural production. the main problem.