If you’re hoping to get lost in the rain on your romantic getaway, check out these details about year-round temperatures in St. Moritz: The hottest months are usually July and August with an average temp of 49°F, while the coldest months are January and February with an average of 19°F. The snowiest months in St. Moritz are April, May, November, and January, with each month seeing an average of 5 inches of snowfall.