How Crowded Is Great Sand Dunes National Park & Preserve in September?

September runs about 1.3× Great Sand Dunes National Park & Preserve's average month, which makes it a busy month here — roughly 11% of the park's yearly visitors come in September.

In a typical September the park sees about 49,000 recreation visits, based on National Park Service monthly counts from 1979 to 2025.

That makes September the 5th-busiest of the park's twelve months, sitting between the June peak (2.4×) and the January low (0.1×).

On our Best Time to Visit score September rates 59/100 ("Fair") — the single best-rated month at Great Sand Dunes, balancing crowds against weather and daylight.

Typical September weather, from 1991–2020 NOAA climate normals at the nearest station, averages a daytime high near 72°F and an overnight low around 44°F, with about 1.3" of precipitation.

That average of about 58°F is a comfortable range for hiking and being outdoors all day.

Because June, July and August together draw about 53% of annual visitors, choosing September instead steps outside that summer crush — the single biggest lever on how crowded the park feels.

You'll have about 12.2 hours of daylight in September to explore — between the 9.4-hour midwinter low and the 14.6-hour summer high.

Park-wide, 2025 drew 432,498 recreation visits, down 1.2% from 437,661 in 2024.

Across the past decade overall visitation has risen about 15.5%, so a September visit is likely to feel busier than it did a few years ago.