Why is the weather in Changsha so diligent recently?

The geographical location and topography of Changsha make the climate in Changsha and even the whole central Hunan more special. There are three main reasons that affect Changsha's climate: First, Changsha is located in the southeast of China and belongs to the world-famous monsoon climate zone. Affected by the monsoon, the seasonal changes are obvious, and Leng Xia is hot in winter; Second, Changsha is located in the third step of China's topography, far from the sea, with plain hills as the main terrain, and the continental climate characteristics of Leng Xia fever in winter are obvious; Thirdly, due to the ups and downs of geological age, the terrain in central Hunan where Changsha is located is high in the south and low in the north, especially Wuling Mountain in the south, Mufu Mountain in the east, Xuefeng Mountain in the west and Dongting Lake in the north, which makes its terrain horseshoe-shaped and blocks the adjustment of the west wind in the East and South China Seas, making the characteristics of cold winter and summer inflammation particularly remarkable. Simply put, Changsha is located in the Xiangjiang River Basin, with high humidity and hot smog in summer (the humidity is close to 90% before it rains, and it feels like being in a sauna. It's very cold in winter (it's windy outside and there's no heating in the house), but spring and autumn are short and the temperature changes greatly. Sometimes a sunny day is summer, and when it rains at night, it becomes winter. Chengdu is located in a basin, with high terrain, less strong convection in the air, little change in climate temperature, warm and humid in winter and high temperature in summer, but usually it is not very hot (that is, things are easy to get moldy), with distinct seasons and similar time distribution. In a word, spring in Changsha is as abnormal as the four seasons.