If you’re looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Fergus Falls: The hottest months are usually July and August, with an average temperature of 20°C, while the coldest months are January and February, with an average of -8°C. The snowiest months in Fergus Falls are March, January, December and February, with each month seeing an average of 14 cm of snowfall.