Planning for the weather is an important factor for making your trip to Mantilhue a success, especially when you're splurging. The hottest months are usually January and February with an average temp of 54°F, while the coldest months are July and August with an average of 39°F. The rainiest months in Mantilhue are June, August, July, and May, with each month seeing an average of 21 inches of rainfall.