If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Yancheng: The hottest months are usually July and August with an average temp of 77°F, while the coldest months are January and February with an average of 41°F. The rainiest months in Yancheng are July, August, June, and September, with each month seeing an average of 8 inches of rainfall.