If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Roberval: The hottest months are usually July and August with an average temp of 61°F, while the coldest months are January and February with an average of 14°F. The snowiest months in Roberval are January, February, November, and December, with each month seeing an average of 41 inches of snowfall.