Planning for the weather is a good way to make your trip to Gatineau relaxing and enjoyable, especially when you’re splurging. The hottest months are usually July and August with an average temp of 65°F, while the coldest months are January and February with an average of 21°F. The snowiest months in Gatineau are January, December, February, and November, with each month seeing an average of 10 inches of snowfall.