If you’re looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Chenggong: The hottest months are usually May and June, with an average temperature of 20°C, while the coldest months are January and December, with an average of 10°C. The rainiest months in Chenggong are June, July, August and September, with each month seeing an average of 239 mm of rainfall.