Manhattan Project National Historical Park in December
December at Manhattan Project National Historical Park averages a daytime high near 40°F and an overnight low around 21°F, with about 0.9" of precipitation and roughly 8" of snow. Visitation runs about 0.5× the park's average month, which makes December a very quiet month here.
- Average low
- 21°F
- Average high
- 40°F
Range across the year: 21°F to 83°F
- Precipitation
- 0.9 in
- Snowfall
- 8 in
- Daylight
- 9.6 hours
Roughly 4% of the park's yearly visitors come in December: roughly 2,500 recreation visits in a typical year, based on National Park Service monthly counts from 2016 to 2025.
That makes December the 10th-busiest of the park's twelve months, sitting between the July peak (1.7×) and the January low (0.3×).
On our Best Time to Visit score December rates 38/100 ("Poor"). Our recommended month is May: pleasant weather with noticeably thinner crowds (shoulder season).
The daily average of about 31°F is cold, with winter conditions likely on higher ground. These figures are 1991–2020 NOAA climate normals from the nearest station, about 1.6 miles from the park.
Because June, July and August together draw about 37% of annual visitors, choosing December instead steps outside that summer crush — the single biggest lever on how crowded the park feels.
You'll have about 9.6 hours of daylight in December 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 December may feel a touch quieter than it once did.
How December compares with the months around it
| Month | Avg high / low | Crowds | Best-time score |
|---|---|---|---|
| November | 50°F / 28°F | 0.7× Quiet | 34 Poor |
| December | 40°F / 21°F | 0.5× Very quiet | 38 Poor |
| January | 40°F / 21°F | 0.3× Very quiet | 43 Poor |
All twelve months at Manhattan Project, with the best time to visit.
Things to do at Manhattan Project in December
The National Park Service tags 45 Manhattan Project activities for winter. Here are 8 of them. Each links to the park's own page for it.
- Hanford: Hike the White Bluffs North Trail · 2-4 hours
- Hanford: Hike the White Bluffs South Slope Trail · 6-8 hours
- Hanford: Tour the Pasco Aviation Museum · 1-2 hours
- Albuquerque: Explore the Indian Pueblo Cultural Center · 1-4 hours
- Hanford: Picnic at Kurtzman Park · 0-1 hours
- Hanford: Visit the Wanapum Heritage Center · 2 hours
- Los Alamos: Learn about Nature on the Pajarito Plateau · 30-60 minutes
- Oak Ridge: Explore the Children's Museum of Oak Ridge · 1-4 hours
Frequently Asked Questions
December averages a daytime high near 40°F and an overnight low around 21°F at Manhattan Project National Historical Park, with about 0.9 inches of precipitation and roughly 8 inches of snow. These are 1991–2020 NOAA climate normals from the nearest station, about 1.6 miles from the park, so conditions inside the park can differ, especially at other elevations.
December is very quiet at Manhattan Project National Historical Park (about 0.5× the average month). Our best-time score rates it "Poor" at 38/100. Our recommended month is May.
The busiest month is July and the quietest is January. December sits at about 0.5× the park's average, or 4% of annual visitation.
A typical December sees about 3,000 recreation visits at Manhattan Project National Historical Park, based on National Park Service monthly counts from 2016–2025.
Where to stay near Manhattan Project in December
Booking a December trip to Manhattan Project National Historical Park? Compare hotels, cabins and vacation rentals near the park with live December availability and prices.
Top-rated places to stay near Manhattan Project
Prices for Oct 30–Nov 1, 4 adults. Change dates on the map below.
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See the full ranking of the best national parks to visit in December.
Source: National Park Service Visitor Use Statistics (2016–2025), NOAA NCEI Climate Normals 1991–2020. Updated 2026-10-11.