Hello, there is no city or province called Jiangnan on the map of China. Jiangnan is the name that Chinese often call the area on the south of the Yangtze River. Actually, you want to know about the weather of Shanghai and the cities in Jiangsu Province, right? The weather of Shanghai is similar to that of Jiangsu, as they are so close. At the end of April, the weather becomes very warm. You can feel the coming of summer. So, prepare some cool clothes like T-shirts, blouse, skirts.