How Crowded Is Great Sand Dunes in September?
September is a busy month at Great Sand Dunes National Park & Preserve, running about 1.3× the park's average month — roughly 11% of the year's visitors come in September. That puts it between the June peak and the January low. Overall our best-time score rates September as "Fair" for a visit. Typical September weather averages a high near 72°F and a low around 44°F, with about 1.3" of precipitation. You'll get about 12.2 hours of daylight to explore.
Frequently Asked Questions
September is busy at Great Sand Dunes National Park & Preserve (about 1.3× the average month). Our best-time score rates it "Fair". The single best month overall is September.
The busiest month is June and the quietest is January. September sits at about 1.3× the park's average, or 11% of annual visitation.
Source: National Park Service Visitor Use Statistics (1979–2025), NOAA NCEI Climate Normals 1991–2020. Updated 2026-06-20.