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 temperature of 19°C, while the coldest months are January and February, with an average of -9°C. The snowiest months in Mahnomen are April, March, December and February, with each month seeing an average of 25 cm of snowfall.