What does the vernal equinox mean? At the vernal equinox, it is warm and cold at first sight.

The vernal equinox is one of the 24 solar terms in China. That is to say, on the vernal equinox, the sun shines directly at the equator, and day and night are almost equal. Then the direct sunlight position gradually moved northward, and the days were long and the nights were short. After the vernal equinox, there will be a cold spring.

When the vernal equinox comes, the climate is mild, the rain is abundant and the sun is shining. Winter crops in most parts of China enter the spring growth stage, which is also the sowing time of early rice. During the spring equinox and solar terms, the East Asian trough is obviously weakened, and the trough ridge activity in the westerly belt is obviously enhanced. From Mongolia to the northeast, there are often low-pressure activities and cyclone development. Low-pressure movement causes cold air to go south, and it is windy and windy in the north. When the long wave trough moves eastward, there will be continuous rainy and cold weather due to the intersection of cold and warm air masses.

Extended data:

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.