Weather is probably a major factor when you plan your trip to Khong Island, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually March and April, with an average temperature of 31°C, while the coldest months are January and December, with an average of 27°C. The rainiest months in Khong Island are August, September, July and June, with each month seeing an average of 416 mm of rainfall.