If you’re looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Chiang Khong: The hottest months are usually April and March, with an average temperature of 26°C, while the coldest months are January and December, with an average of 21°C. The rainiest months in Chiang Khong are August, July, September and May, with each month seeing an average of 280 mm of rainfall.