How Crowded Is Cumberland Island National Seashore in September?

September runs about 0.6× Cumberland Island National Seashore's average month, which makes it a quiet month here — roughly 5% of the park's yearly visitors come in September.

In a typical September the park sees roughly 3,300 recreation visits, based on National Park Service monthly counts from 1979 to 2025.

That makes September the 11th-busiest of the park's twelve months, sitting between the March peak (1.6×) and the January low (0.6×).

On our Best Time to Visit score September rates 74/100 ("Good"), versus the top-rated October at 76/100 — 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 85°F and an overnight low around 71°F, with about 5.2" of precipitation.

That average of about 78°F is warm enough that midday heat is worth planning around.

Because June, July and August together draw about 26% 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 10-hour midwinter low and the 14-hour summer high.

Park-wide, 2025 drew 60,299 recreation visits, down 6.8% from 64,706 in 2024.

Across the past decade overall visitation has risen about 18.4%, so a September visit is likely to feel busier than it did a few years ago.