Fort Union National Monument in May
May at Fort Union National Monument averages a daytime high near 75°F and an overnight low around 38°F, with about 1.5" of precipitation. Visitation runs about 1.3× the park's average month, which makes May a busy month here.
- Average low
- 38°F
- Average high
- 75°F
Range across the year: 14°F to 88°F
- Precipitation
- 1.5 in
- Daylight
- 13.9 hours
Roughly 11% of the park's yearly visitors come in May: roughly 1,200 recreation visits in a typical year, based on National Park Service monthly counts from 1979 to 2025.
That makes May the 3rd-busiest of the park's twelve months, sitting between the June peak (1.7×) and the January low (0.3×).
On our Best Time to Visit score May rates 51/100 ("Fair"). Our recommended month is October: the lightest crowds of the park's good-weather months.
The daily average of about 57°F is a comfortable range for hiking and being outdoors all day. These figures are 1991–2020 NOAA climate normals from the nearest station, about 8 miles from the park.
Because June, July and August together draw about 37% of annual visitors, choosing May instead steps outside that summer crush — the single biggest lever on how crowded the park feels.
You'll have about 13.9 hours of daylight in May to explore — between the 9.6-hour midwinter low and the 14.4-hour summer high.
Park-wide, 2024 drew 9,217 recreation visits, down 3.7% from 9,570 in 2023.
Across the past decade overall visitation has eased about 12.5%, so May may feel a touch quieter than it once did.
How May compares with the months around it
| Month | Avg high / low | Crowds | Best-time score |
|---|---|---|---|
| April | 67°F / 29°F | 1.0× Average | 47 Fair |
| May | 75°F / 38°F | 1.3× Busy | 51 Fair |
| June | 85°F / 46°F | 1.7× Very busy | 52 Fair |
All twelve months at Fort Union, with the best time to visit.
Frequently Asked Questions
May averages a daytime high near 75°F and an overnight low around 38°F at Fort Union National Monument, with about 1.5 inches of precipitation. These are 1991–2020 NOAA climate normals from the nearest station, about 8 miles from the park, so conditions inside the park can differ, especially at other elevations.
May is busy at Fort Union National Monument (about 1.3× the average month). Our best-time score rates it "Fair" at 51/100. Our recommended month is October.
The busiest month is June and the quietest is January. May sits at about 1.3× the park's average, or 11% of annual visitation.
A typical May sees about 1,000 recreation visits at Fort Union National Monument, based on National Park Service monthly counts from 1979–2025.
Where to stay near Fort Union in May
Booking a May trip to Fort Union National Monument? Compare hotels, cabins and vacation rentals near the park with live May availability and prices.
Top-rated places to stay near Fort Union
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See the full ranking of the best national parks to visit in May.
Source: National Park Service Visitor Use Statistics (1979–2025), NOAA NCEI Climate Normals 1991–2020. Updated 2026-10-11.