Weather is probably a major factor when you plan your trip to Khlong Yai, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually April and March with an average temp of 81°F, while the coldest months are January and February with an average of 78°F. The rainiest months in Khlong Yai are September, July, August, and June, with each month seeing an average of 20 inches of rainfall.