How Crowded Is Castillo de San Marcos in April?
April is a busy month at Castillo de San Marcos National Monument, running about 1.2× the park's average month — roughly 10% of the year's visitors come in April. That puts it between the March peak and the September low. Overall our best-time score rates April as "Good" for a visit. Typical April weather averages a high near 80°F and a low around 61°F, with about 2.9" of precipitation. You'll get about 12.7 hours of daylight to explore.
Frequently Asked Questions
April is busy at Castillo de San Marcos National Monument (about 1.2× the average month). Our best-time score rates it "Good". The single best month overall is October.
The busiest month is March and the quietest is September. April sits at about 1.2× the park's average, or 10% of annual visitation.
Source: National Park Service Visitor Use Statistics (1979–2025), NOAA NCEI Climate Normals 1991–2020. Updated 2026-06-20.