How Crowded Is Thaddeus Kosciuszko National Memorial in September?

September runs about 1.2× Thaddeus Kosciuszko National Memorial's average month, which makes it a busy month here — roughly 10% of the park's yearly visitors come in September.

In a typical September the park sees about 510 recreation visits, based on National Park Service monthly counts from 1981 to 2025.

That makes September the 4th-busiest of the park's twelve months, sitting between the July peak (1.8×) and the January low (0.4×).

On our Best Time to Visit score September rates 58/100 ("Fair"), versus the top-rated October at 55/100 — pleasant weather with noticeably thinner crowds (shoulder season).

Typical September weather, from 1991–2020 NOAA climate normals at the nearest station, averages a daytime high near 80°F and an overnight low around 63°F, with about 4.9" of precipitation.

That average of about 72°F is a comfortable range for hiking and being outdoors all day.

Because June, July and August together draw about 39% 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 9.2-hour midwinter low and the 14.8-hour summer high.

Park-wide, 2013 drew 1,682 recreation visits, down 17.8% from 2,045 in 2012.

Across the past decade overall visitation has eased about 49%, so September may feel a touch quieter than it once did.