Why are the four largest furnaces in my country not located in cities near the Tropic of Cancer?

my country's "Three Great Furnaces" are located in the three famous cities along the Yangtze River: Chongqing, Wuhan, and Nanjing. It is very hot here all day long, and even the lowest temperature is very high and very hot. The lowest temperature on some days is around 28 degrees. According to meteorological observatory research, the highest temperature in a day ≥35 degrees is called a "hot day", and there are 15 to 35 hot days in the three cities every year, and "hot days" of ≥37 degrees often occur. "Hot Days", among which Chongqing has the most hot days. In history, the highest temperatures in the three cities are mostly above 40 degrees, so they are known as the "Three Great Furnaces". Why are these three places so hot? First, In July and August every year, after the rainy season in the middle and lower reaches of the Yangtze River, the high-pressure temperature controls the area, causing the lower airflow to move and form a dry weather that makes it difficult for clouds and rain to form. The surface temperature of the ground is very high. According to measurements, on extremely hot days, the maximum temperature of the ground can be Reaching 65 to 70 degrees. Second, the three famous cities are located in the valley areas of the Yangtze River Basin. The altitude is low, and the ground temperature and heat are not easily lost, so most of the heat is preserved. In addition, the air flows from the high altitudes into the valleys, not only preventing the formation of clouds and rain, but also preventing the formation of clouds and rain. The temperature is getting higher and higher. At the same time, there are rice fields crisscrossing the Yangtze River and dense river networks. There is a lot of oxygen in the air and the humidity is very high. The high temperature and high humidity climate makes it difficult for human sweat to evaporate, making people feel very stuffy. Third, because there is a lack of cool breeze in summer here. The air flow is mainly sinking, the atmosphere is very stable, there is not even a trace of wind, which accelerates the hot atmosphere here.

Fujian, Guangdong, and Guangxi near the Tropic of Cancer are close to the sea and are affected by the maritime climate, so they are relatively cooler, but they are often hit by typhoons