Weather is probably a major factor when you plan your trip to Phimai, 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 December and January with an average of 77°F. The rainiest months in Phimai are September, August, October, and July, with each month seeing an average of 9 inches of rainfall.