Weather will likely play an important role when you plan your trip to Sisaket, 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 85°F, while the coldest months are January and December with an average of 77°F. The rainiest months in Sisaket are September, July, August, and June, with each month seeing an average of 13 inches of rainfall.