Fall is a pleasant time to visit Great Sand Dunes National Park. The National Park Service says temperatures usually reach the 60s or 70s during the day and drop to the 20s and 30s at night. Remember, this is Colorado so a fall snowstorm isn’t out of the question.
Winters are generally sunny, but temperatures can be brutally cold and snow is common.
For many people, spring is the time to visit. Snowmelt brings water to Medano Creek and the area around it becomes a beach atmosphere late in the season. Temperatures may reach the 60s but strong winds are common.
Summer can be hot in the dunes, with sand temperatures reaching 140 degrees. Summer daytime highs average in the low 80s.