Four months. Generally speaking, the summer in Nanchang begins at the end of May or early June and ends at the end of September or early June 10, in which July and August are the hottest two months, so the summer in Nanchang can be said to last for four months. Nanchang, a prefecture-level city in Jiangxi Province, People's Republic of China (PRC), is located in the north-central part of Jiangxi Province, downstream of Ganjiang River and Fuhe River, and southwest of Poyang Lake.