Planning for the weather is a good way to make your trip to Champex-Lac relaxing and enjoyable, especially when you’re splurging. The hottest months are usually July and August, with an average temperature of 12°C, while the coldest months are January and February, with an average of -6°C. The rainiest months in Champex-Lac are May, July, June and December, with each month seeing an average of 198 mm of rainfall.