Planning for the weather is an important factor for making your trip to Susanville a success, especially when you’re splurging. The hottest months are usually July and August with an average temp of 68°F, while the coldest months are December and January with an average of 32°F. The snowiest months in Susanville are March, February, January, and April, with each month seeing an average of 7 inches of snowfall.