Why is there a saying that there is a spring rain and a warmth? Please, 3Q.

1. The proverb "Spring rain brings warmth" is circulated among the people in China. Is there any scientific reason in this? Meteorologists explain this. Spring is the transition season from winter to summer, with frequent cold and warm air activities. In spring, the strength of warm and humid air from the ocean gradually increases, and it is transported to the north every few days. In the middle and lower reaches of the Yangtze River, it meets the cold air from the north, forming precipitation again and again. But the final trend is that the cold air gradually weakens and the warm air increases. Warm air goes north again and again, and the temperature is higher every time. Every time after the spring rain, people have the feeling of "a spring rain and a warmth". Specifically, there are two situations: one is that warm and humid air pushes northward and slides upward at the boundary of cold air in the north, resulting in rainfall. In the process of sliding upwards, the cold air is pushed to the north at the same time. As a result, warm air often occupies the ground originally occupied by cold air. Before the warm air comes, these places often have a spring rain first. The feeling of "a spring rain and a warmth" is this truth. There is another situation: after a place rains, it warms under the control of warm air. If cold air strikes the south in the future, it will rain again. When the cold air front passed, this place was controlled by cold air, and it was relatively cold for a while. But after a day or two, this cold air absorbed a lot of solar radiation heat and was influenced by the warm ground, which made its temperature rise and gradually became warm air. This phenomenon is called air mass degradation in meteorology. So people always think that it is always warm after the rain in spring, as long as the weather is good. In short, winter goes to spring, spring goes to summer, and spring comes, and the weather always develops in a warm direction. A spring rain and a warm weather also illustrate the general development trend of the weather. But sometimes, the cold and warm air are evenly matched, and the areas where they meet often form continuous rainy weather. The sky was covered with thick clouds and there was no sunshine for many days. At the same time, when rainwater evaporates, it will absorb a lot of heat from the ground and nearby air, and the air temperature will decrease. If the spring rain lasts for a long time, there will be cold and rainy weather, so there is also a saying that it is cold and rainy in spring. 2. The agricultural proverb "an autumn rain and a cold" is in line with the objective laws of climate. When autumn comes, the climate changes obviously. At this time, the sky is high and the clouds are light, and the wind is cool, not as hot as summer. At the same time, the cold air in the north often goes south into the lower reaches of the Yangtze River and meets the warm and humid air in the south to form rainfall. Cold air intrusion again and again will often cause rain again and again and cool down again and again. In addition, when the direct sunlight gradually moves southward, the heat absorbed by the ground decreases day by day, which is also beneficial to the enhancement and continuous southward movement of cold air.