Planning for the weather is a good way to make your trip to De Forest relaxing and enjoyable, especially when you’re splurging. 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 -4°C. The snowiest months in De Forest are January, December, March and November, with each month seeing an average of 22 cm of snowfall.