Planning for the weather is a good way to make your trip to Khong Island relaxing and enjoyable, especially when you're splurging. The hottest months are usually March and April with an average temp of 87°F, while the coldest months are January and December with an average of 81°F. The rainiest months in Khong Island are August, September, July, and June, with each month seeing an average of 16 inches of rainfall.