Planning for the weather is an important factor for making your trip to Ixtapan de la Sal a success, especially when you're splurging. The hottest months are usually April and May with an average temp of 72°F, while the coldest months are January and December with an average of 66°F. The rainiest months in Ixtapan de la Sal are September, June, August, and July, with each month seeing an average of 12 inches of rainfall.