How is the rain solar term formed?

Rain is the second of the 24 solar terms. Finger-pointing yin; The sun reaches longitude 330; February 18-20 of the Gregorian calendar every year. Rain solar term means the beginning of rainfall, which is mostly light rain or Mao Mao rain. Proper precipitation is very important for the growth of crops, and it is the reflection of farming culture on festivals. Entering the rain solar term, there is no breath of spring in the northern part of China, but most places in the south are full of spring and a scene of early spring. [7][8][ 16]

The rain solar term generally starts from February 18 to 20 and ends on March 4 or 5. In rainy and solar terms, the direct point of the sun is gradually approaching the equator from the southern hemisphere. At this time, the sunshine hours and intensity in the northern hemisphere are increasing, and the temperature is rising rapidly. Warm and humid air from the ocean becomes active and gradually pushes northward to meet with cold air, forming rainfall. The rainy season is changeable, which is one of the seasons with the most cold wave processes in the whole year, with cold and hot, warm and cold at first. Rain solar term means the beginning of rainfall, but the rainfall is mainly light rain or Mao Mao rain. In rainy and solar terms, the direct point of the sun is gradually approaching the equator from the southern hemisphere. At this time, the sunshine hours and intensity in the northern hemisphere are increasing, and the temperature is rising rapidly. Warm and humid air from the ocean becomes active and gradually pushes northward. At the same time, cold air is not to be outdone in the weakening trend, and it frequently competes with warm air to form rainfall.

Rain is one of the twenty-four solar terms. There are four seasons in a year, three months in spring, summer, autumn and winter, and two solar terms in each month. Each solar term has its own unique meaning. Rainwater solar terms usually mean that rainfall begins and gradually increases. Wu Cheng's book "Twenty-four Solar Terms" in the Yuan Dynasty said: "The first month is aquatic in the sky, and spring is wood. However, people who grow trees must have water, so it rained successfully in beginning of spring. If the east wind melts, it will disperse into rain. "