Planning for the weather is a good way to make your trip to Nantong relaxing and enjoyable, especially when you’re splurging. The hottest months are usually August and July with an average temp of 78°F, while the coldest months are January and February with an average of 44°F. The rainiest months in Nantong are July, June, August, and September, with each month seeing an average of 7 inches of rainfall.