In spring, due to the gradual strengthening of the sun in the northern hemisphere, the warm air in the Pacific Ocean extends to the northwest. When warm air pushes north and rises at the boundary of cold air in the north, it will rain. In the process of sliding upwards, the cold air is pushed to the north at the same time. In this way, warm air often occupies the ground originally occupied by cold air, so before the arrival of warm air, there will often be a spring rain in these places. The feeling of "a spring rain and a warmth" is this truth. When it rains in a place, it gets warmer under the control of warm air, and then it will rain again if the cold air bounces south. When the cold air front passed, it was controlled by cold air, and there was a cold weather for a day or two. But in a few days, this cold air will absorb a lot of solar radiation heat, and it will gradually become warm air because of the influence of the warm land in the south. So people always think that it is always warm after the rain in spring, as long as the weather is good.

Besides, why is it getting colder every day in autumn? This is mainly because the direct rays of the sun gradually move southward, and the light and heat irradiated by the northern hemisphere decrease day by day, which is also conducive to the enhancement and southward movement of cold air. After several cold air flows southward, the local temperature became very low. People often say that "an autumn rain and a cold" is the truth.