How Crowded Is Manhattan Project National Historical Park in January?

January runs about 0.3× Manhattan Project National Historical Park's average month, which makes it a very quiet month here — roughly 3% of the park's yearly visitors come in January.

In a typical January the park sees roughly 1,600 recreation visits, based on National Park Service monthly counts from 2016 to 2025.

It is the quietest month of the year at Manhattan Project; by contrast July, the busiest, runs about 1.7× the average — so January is the easiest time to have the place largely to yourself.

On our Best Time to Visit score January rates 43/100 ("Poor"), versus the top-rated May at 56/100 — pleasant weather with noticeably thinner crowds (shoulder season).

Typical January weather, from 1991–2020 NOAA climate normals at the nearest station, averages a daytime high near 40°F and an overnight low around 21°F, with about 0.9" of precipitation and roughly 10" of snow.

That average of about 30°F is cold, with winter conditions likely on higher ground.

Because June, July and August together draw about 37% of annual visitors, choosing January instead steps outside that summer crush — the single biggest lever on how crowded the park feels.

You'll have about 9.8 hours of daylight in January to explore — near the year-round minimum.

Park-wide, 2025 drew 56,390 recreation visits, down 24.5% from 74,693 in 2024.

Across the past decade overall visitation has eased about 43.1%, so January may feel a touch quieter than it once did.