What is the meaning of "one autumn rain and one cold, ten autumn rains need to wear cotton"

"One autumn rain and one cold, ten autumn rains need to wear cotton" is a folk proverb, which means that it will be almost two and a half months after beginning of autumn, during which the next rain will make the weather colder; If there are ten autumn rains, it means that the clothes are getting thicker. Ten autumn rains are a rough figure, not necessarily ten.

It will get cold after an autumn rain because the sun's rays gradually move south after autumn, and the north will take this opportunity to accumulate cold air and meet the warm and humid airflow in the south, so there will be rainy weather.

Extended data

A scientific explanation of an autumn rain and a cold;

In autumn, cold air travels south from Siberia and Mongolia and enters most parts of China. When it meets the warm and humid air in the south, it forms rain. The cold air going south again and again often causes rainfall again and again, lowering the local temperature again and again.

In addition, at this time, 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 the cold air went south several times, the local temperature became very low This is the truth of "an autumn rain and a cold".