Why is the climate in Wuhan so extreme?

Wuhan has a subtropical monsoon humid climate with abundant rainfall and sunshine, with hot summer and cold winter. The average annual temperature is 15.8℃- 17.5℃. In a year, the average temperature is the lowest, at 65438 0.4℃. The highest average temperature in July and August is 28.7℃. Summer is as long as 135 days. Because Wuhan is located at 30 degrees north latitude, the height of the sun can reach 38 degrees at noon in summer, and it is located inland and far from the ocean. The terrain is like a basin, which is easy to collect heat and difficult to dissipate heat. There are many rivers and lakes, and there is much water vapor at night. Coupled with the urban heat island effect and the control of subtropical high in summer, it is very stuffy. It is one of the three largest stoves in China, with an extreme maximum temperature of 44.5 degrees in summer. The rainy season in early summer is concentrated, with annual precipitation 1 100 mm, Wuhan active accumulated temperature "5 150℃, annual frost-free period of 240 days and total sunshine hours of 2000 hours.