If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Algonquin Highlands: The hottest months are usually July and August with an average temp of 62°F, while the coldest months are January and February with an average of 18°F. The snowiest months in Algonquin Highlands are February, January, December, and April, with each month seeing an average of 39 inches of snowfall.