China's "three stoves" refers to which three places?

Chongqing, Wuhan and Nanjing are famous high temperature centers in summer in China, and are known as the "three furnaces" in the Yangtze River basin. Their popularity is second only to Turpan in Xinjiang. Every year to the midsummer of July, the sun is shining, there is no wind in the fields, and the temperature is always above 30℃. At the hottest time, Chongqing reached 44℃, Wuhan 42.2℃ and Nanjing 43℃. In the evening, although the sun sets in the west, the summer heat is still gone. Unlike Shanghai, although it is very hot during the day, there is a cool breeze at night to cool off the heat. Even if there is a little wind in these places, it is uncomfortable to be hot.