How Crowded Is Castillo de San Marcos National Monument in October?

October runs about 0.6× Castillo de San Marcos National Monument's average month, which makes it a quiet month here — roughly 5% of the park's yearly visitors come in October.

In a typical October the park sees about 33,000 recreation visits, based on National Park Service monthly counts from 1979 to 2025.

That makes October the 11th-busiest of the park's twelve months, sitting between the March peak (1.5×) and the September low (0.6×).

On our Best Time to Visit score October rates 77/100 ("Excellent") — the single best-rated month at Castillo de San Marcos, balancing crowds against weather and daylight.

Typical October weather, from 1991–2020 NOAA climate normals at the nearest station, averages a daytime high near 82°F and an overnight low around 67°F, with about 4.4" of precipitation.

That average of about 74°F is a comfortable range for hiking and being outdoors all day.

Because June, July and August together draw about 24% of annual visitors, choosing October instead steps outside that summer crush — the single biggest lever on how crowded the park feels.

You'll have about 11.3 hours of daylight in October to explore — between the 10.1-hour midwinter low and the 13.9-hour summer high.

Park-wide, 2025 drew 598,070 recreation visits, up 3.1% from 579,825 in 2024.

Across the past decade overall visitation has eased about 13.4%, so October may feel a touch quieter than it once did.