Planning for the weather is a good way to make your trip to Courmayeur relaxing and enjoyable, especially when you’re splurging. The hottest months are usually July and August with an average temp of 55°F, while the coldest months are January and February with an average of 25°F. The rainiest months in Courmayeur are December, May, January, and June, with each month seeing an average of 8 inches of rainfall.