Weather will likely play an important role when you plan your trip to Roi Et, but bear 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 temperature of 30°C, while the coldest months are January and December, with an average of 25°C. The rainiest months in Roi Et are September, July, August and May, with each month seeing an average of 285 mm of rainfall.