If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Moosomin: The hottest months are usually July and August with an average temp of 63°F, while the coldest months are February and January with an average of 12°F. The snowiest months in Moosomin are March, November, December, and January, with each month seeing an average of 12 inches of snowfall.