You'll likely spend much of your trip indoors, but if you want to see more of the area, looking at local weather trends is a good idea. 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 15°F. The snowiest months in Mahnomen are April, March, December, and February, with each month seeing an average of 10 inches of snowfall.