If you’re looking forward to lots of outings with your partner, check out these details about year-round temperatures in Leppäjärvi: The hottest months are usually July and August with an average temp of 50°F, while the coldest months are January and February with an average of 13°F. The snowiest months in Leppäjärvi are January, March, February, and April, with each month seeing an average of 120 inches of snowfall.