If you’re hoping to get lost in the rain on your romantic getaway, check out these details about year-round temperatures in St. Stephen: The hottest months are usually July and August with an average temp of 63°F, while the coldest months are January and February with an average of 25°F. The snowiest months in St. Stephen are January, February, December, and March, with each month seeing an average of 15 inches of snowfall.