If you’re looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Farmington: 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 0°C. The snowiest months in Farmington are January, December, February and November, with each month seeing an average of 77 cm of snowfall.