Three Furnaces
The term Three Furnaces refers to the especially hot and oppressively humid summer weather in several major cities in the Yangtze River Valley, within China. It was coined during the ROC period of China, and refers to the following cities:
Sometimes, Changsha or Nanchang are added, making the Four Furnaces. In addition to the above 5 cities, Hangzhou and Shanghai are added to form the Seven Furnaces.
Yet the above names originate mainly from popular opinion, not necessarily on the basis of data. The next seven hottest cities, are Changsha, Wuhan, Haikou, Nanchang, Guangzhou, Xi'an, and Nanning. Unlike the other cities, Xi'an, the capital of Shaanxi province, lies within the northwest.