Taking into account the local weather in Gunnison is an important factor for planning your visit, especially if you plan to spend your trip poolside. The hottest months are usually July and August with an average temp of 59°F, while the coldest months are January and December with an average of 19°F. The snowiest months in Gunnison are January, February, March, and December, with each month seeing an average of 11 inches of snowfall.