If you’re hoping to get lost in the rain on your romantic getaway, check out these details about year-round temperatures in Carleton Place: 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 Carleton Place are January, December, February, and November, with each month seeing an average of 10 inches of snowfall.