Planning for the weather is a good way to make your trip to Fortim relaxing and enjoyable, especially when you're splurging. The hottest months are usually September and October with an average temp of 81°F, while the coldest months are July and August with an average of 80°F. The rainiest months in Fortim are March, April, February, and May, with each month seeing an average of 7 inches of rainfall.