How Crowded Is Castle Clinton in December?
December is an average month at Castle Clinton National Monument, running about 0.9× the park's average month — roughly 7% of the year's visitors come in December. That puts it between the July peak and the January low. Overall our best-time score rates December as "Poor" for a visit. Typical December weather averages a high near 44°F and a low around 34°F, with about 4.4" of precipitation and roughly 4.9" of snow. You'll get about 9.1 hours of daylight to explore.
Frequently Asked Questions
December is average at Castle Clinton National Monument (about 0.9× the average month). Our best-time score rates it "Poor". The single best month overall is September.
The busiest month is July and the quietest is January. December sits at about 0.9× the park's average, or 7% of annual visitation.
Source: National Park Service Visitor Use Statistics (1979–2025), NOAA NCEI Climate Normals 1991–2020. Updated 2026-06-20.