20 13 why is it so hot in summer? What is the reason?

The reasons for this rare high temperature can be summarized into three points:

First of all, the rainy season in the middle and lower reaches of the Yangtze River is shorter than in previous years, and plum blossoms come out earlier. Since the beginning of July, the subtropical high has been continuously controlling the middle and lower reaches of the Yangtze River. Affected by downdraft, the weather is sunny, partly cloudy, with strong solar radiation and high atmospheric humidity.

Secondly, the intensity of subtropical high is obviously stronger than that of the same period in history. Last year, the middle and lower reaches of the Yangtze River were rainy in the first half of July, but this year, due to the early plum blossom, the number of high temperature days was obviously higher and the subtropical high was stronger, which led to the continuous rise of temperature.

Third, the atmospheric circulation is abnormal. So far, almost no typhoons have moved northward and inland. In previous years, because of the typhoon landing, the subtropical high will shrink and break under the influence of the typhoon, and the weather also presents a weather situation in which the typhoon cools down for a while, which is called intermittent high temperature.

This year's typhoon affected the south, mainly in the Taiwan Province Strait and the South China Sea, which caused the subtropical high to control the inland for a long time, and it is reasonable that the middle and lower reaches of the Yangtze River suffered from high temperature for a long time.