Two ancient poems, one saying "it will be sunny when the plum is yellow" and the other saying "it rains at home during the Huangmei season", then is it rainy or sunny during the Huangmei season?

In fact, this has something to do with geographical knowledge. Because the middle and lower reaches of the Yangtze River belong to the eastern monsoon region of China, its weather is deeply influenced by the monsoon. The summer monsoon in China is unstable. In normal years, the middle and lower reaches of the Yangtze River enter the rainy season in June, and the rain keeps falling, so there is a saying that it rains at home in Huangmei season. In the year when the subtropical high is strong, the subtropical high accelerates to move northward, so the middle and lower reaches of the Yangtze River will be in the zone controlled by the subtropical high in June, and the downward airflow will prevail, and the weather will be sunny and dry, which is the so-called empty plum brings sunny days.

These two ancient poems describe Hangzhou. Generally speaking, Hangzhou enters summer at the end of May, but it is cool most of the time in June, which can be regarded as the welfare of the college entrance examination. It rained most of the time, and it stopped raining, which is the sultry smell of summer. As long as it rains, it won't be too hot. This situation generally lasts until the end of June, and basically blooms in July, followed by high-pressure controlled summer, commonly known as barbecue mode.

It can be seen that the two poets are in different periods when describing Huangmei season. The rainy season in the middle and lower reaches of the Yangtze River is the result of the quasi-static front stop in Jianghuai, and the cold and warm air mass forces the front to swing back and forth. At this time, the air pressure near the surface of the cold air mass in the Jianghuai area is higher than that of the warm air mass. The high temperature weather in South China is caused by the high altitude angle of the sun in midsummer. At this time, the convection is active and the local air pressure near the ground is low. The hot weather in the middle and lower reaches of the Yangtze River is due to the summer drought, which is controlled by the subtropical high and the air pressure is high.

However, it must be said that the two poets' descriptions of Huangmei season have their own characteristics and are very beautiful. It seems that the ancients had a good understanding of the climate and environment.