Climate along the San Juan Skyway and the best times of year to visit.

San Jaun Skyway Climate
Climate scientists have been systematically studying climate changes at all elevations in the San Juan Mountains (SJM) over much of the 20th century. Like much of the rest of the world, temperature changes have occurred in the SJM due to global climatic factors. Western Colorado and its SJM have warmed by 1 °C since 1895, mostly since 1990. Climate scientists are continuing their analysis of changes in temperatures, precipitation, snow cover, cloud cover, and other climate trends in the SJM area and the rest of Colorado. But the good and reassuring news for residents and visitors to the SJM is that trends in temperature, snow covering and precipitation changes during summer, spring, fall and winter still leave the region with marvelous scenery and ample opportunities for outdoor fun and adventure.
Colorado Autumn

The weather in the SJM can go to extremes. One day eight inches of rain poured down (Gladstone). But there are years when it hasn’t rained at all in the month of June. Purgatory has seen 62 inches of snow in one day and 144 inches in a week. However, for the purpose of comparisons: the SJM get 24 inches of rain, on average, per year, and the US average is 38 inches of rain per year; SJM averages 163 inches of snow per year; the US average is 28 inches of snow per year; on average, there are 251 sunny days per year in the SJM and the US average is 205 sunny days; and more than 100 days a year there is some form of precipitation in the SJM. Winter is the wettest season in the SJM, for which skiers are thankful. However, August usually is the wettest month and June is the driest. Summer high temperature in July is around 75 degrees.

All of these variations in weather statistics add up to spring, summer and fall seasons in which visitors can expect brilliant colors in the foliage at various stages of blooming. Fortunately, climate change has not prevented spring flowers from blooming in the valleys and continuing to climb up into the mountains. Nature’s colorful carpet in the SJM lasts into August when nature reverses and red, orange and yellow blooms work their ways back down mountains into the valleys, with plant life showing differences on different slopes at different elevations. In the foothills (5000-7500 ft.), spring comes to the SJM in April or as late as June. In the fall Aspens burst over hillsides with magnificent colors. Above, from 9,000 ft. to timberline, spruce and fir predominate.

Snowy Mountain Top

Bear in mind that the climate of the San Juans varies radically from area to area. Generalizations are impossible. The thermometer rarely drops below zero in Ouray in the winter when 45-degree days are common. Only 25 miles away in Silverton the temperature drops below zero almost every night in the winter. But Silverton’s high temperatures often are higher than Ouray. Summers stay very comfortable with highs in the seventies and eighties. Autumn brings warm days and chilly nights. In other words, from the perspectives of climate and weather, the San Juan Mountains offer a vast variety of different vacation experiences. There is no “best time” to visit the SJM. Pick a season and research weather conditions before making a travel destination decision.

Durango provides a good example of what to expect – without guarantees! Durango sits at 6,512 feet above sea level and enjoys an ideal four-season climate with moderate temperatures year-round. Durango winters are usually mild and sunny with temperatures staying between 10 and 50 degrees. Despite Durango’s snowfall that averages about 71″ each year, snow removal is manageable because Durango is in a low, sun-drenched valley. Spring brings warmer weather and rain (annual precipitation of 19″ per year). Summer temperatures seldom climb more than the high 80s and rivers and reservoirs stay relatively full in summer, filled by melting snow from deep winter snows in the SJM. Fall days are comfortably cool and dry, the perfect time for a mountain hike or a drive on one of the area’s Scenic Byways.