Why is it warm in the vernal equinox?

Because the sun shines directly on the equator on the vernal equinox, the day and night are almost equal. After that, the position of direct sunlight begins to move northward gradually, and the days are long and the nights are short. Climatically, the vernal equinox also has obvious characteristics. During the vernal equinox, China has entered spring except the northwest, northeast, Qinghai-Tibet Plateau and northern North China. Just a few days later, when "99 plus a long time, cattle are walking everywhere", the frozen soil layer has completely melted, the atmosphere is connected, and the fields are full of vitality.

The vernal equinox is an important solar term, which not only has astronomical significance: the northern and southern hemispheres are equally divided day and night, but also has obvious characteristics in climate. During the vernal equinox, many areas in China enter bright spring, and on the vast land, willows are green, yingfei grass grows, wheat jointing and rape blossoms are fragrant.