How Crowded Is Fort Union Trading Post National Historic Site in September?

September runs about 1.4× Fort Union Trading Post National Historic Site'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 roughly 1,400 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 (3.6×) and the January low (0.1×).

On our Best Time to Visit score September rates 68/100 ("Good"), versus the top-rated August at 71/100 — best overall balance of crowds, weather and daylight.

Typical September weather, from 1991–2020 NOAA climate normals at the nearest station, averages a daytime high near 75°F and an overnight low around 46°F, with about 1.4" of precipitation.

That average of about 60°F is a comfortable range for hiking and being outdoors all day.

Because June, July and August together draw about 65% 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 12.3 hours of daylight in September to explore — between the 8.2-hour midwinter low and the 15.8-hour summer high.

Park-wide, 2024 drew 12,028 recreation visits, down 7.1% from 12,942 in 2023.

Across the past decade overall visitation has eased about 23.2%, so September may feel a touch quieter than it once did.