Why is it so cold in spring?

Because it is a transitional season, the last season is winter.

As far as solar terms are concerned, spring in China begins in the beginning of spring (February 2-5) and ends in the long summer (May 5-7). In Europe and America, spring begins at the vernal equinox in China and ends at the summer solstice. In Ireland, February to April is designated as spring.

Spring is one of the four seasons. As far as solar terms are concerned, spring begins in early spring and ends in long summer. Twenty-four solar terms are the product of ancient farming civilization in China, and the division of four seasons begins with "four stands". In the historical development, cultural exchange and communication, four solar terms (vernal equinox, autumnal equinox, summer solstice, winter solstice) reflecting the return movement of the direct point of the sun were all over the pre-Qin period. The division of the four seasons in the west is based on the dichotomy, that is, spring is divided into beginning of spring.

The vernal equinox in the "vernal equinox" is also the New Year of Uzbekistan, Turkey, Afghanistan, Iran and other countries, with a history of more than 3,000 years. In Ireland, February to April is designated as spring. In spring, the northern hemisphere of the earth began to tilt towards the sun, receiving more and more direct sunlight, so the temperature began to rise.