When is the best time of year to visit Colorado? The four seasons in the Gunnison Valley are distinct, each with its own unique beauty. Spring, summer, fall and winter feature different weather, outdoor activities and events. This guide to Colorado’s seasons will help you pick the best time to plan your trip to Crested Butte and Gunnison based on your preferred activities. It will also give you a sense of what the weather will be like when you visit Colorado.