Why is it warm in the vernal equinox?

Because the sun shines directly at the equator at the vernal equinox, day and night are almost equal. After that, the position of direct sunlight began to move northward gradually, and the days began to get longer and the nights became shorter. Climatically, the vernal equinox also has obvious characteristics. During the spring equinox, except the northwest, northeast, Qinghai-Tibet Plateau and northern North China, all other areas in China have entered spring. Only a few days later, when "99 plus a long time, cows 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. At the vernal equinox, many areas in China enter bright spring. On the vast land, willows are green, yingfei grass grows, wheat jointing and rape blossoms.