Isle Royale National Park in May
May at Isle Royale National Park averages a daytime high near 58°F and an overnight low around 37°F, with about 3.1" of precipitation. Visitation runs about 0.5× the park's average month, which makes May a very quiet month here.
- Average low
- 37°F
- Average high
- 58°F
Range across the year: 1°F to 74°F
- Precipitation
- 3.1 in
- Daylight
- 15.0 hours
Roughly 4% of the park's yearly visitors come in May: about 830 recreation visits in a typical year, based on National Park Service monthly counts from 1979 to 2025.
That makes May the 5th-busiest of the park's twelve months, sitting between the August peak (4.2×) and the January low (0×).
On our Best Time to Visit score May rates 71/100 ("Good"). Our recommended month is September: the lightest crowds of the park's good-weather months.
The daily average of about 47°F is cool, so layers and a shorter daylight window matter. These figures are 1991–2020 NOAA climate normals from the nearest station, about 40 miles from the park.
Because June, July and August together draw about 83% 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 15 hours of daylight in May to explore — between the 8.2-hour midwinter low and the 15.8-hour summer high.
Park-wide, 2019 drew 26,410 recreation visits, up 2.4% from 25,798 in 2018.
Across the past decade overall visitation has risen about 56.7%, so a May visit is likely to feel busier than it did a few years ago.
How May compares with the months around it
| Month | Avg high / low | Crowds | Best-time score |
|---|---|---|---|
| April | 45°F / 26°F | 0.0× Very quiet | 10 Poor |
| May | 58°F / 37°F | 0.5× Very quiet | 71 Good |
| June | 68°F / 46°F | 2.1× Very busy | 65 Good |
All twelve months at Isle Royale, with the best time to visit.
Seasonal closures in May 2027
The National Park Service lists these Isle Royale facilities as closed during May 2027. The dates are the park's own, read on October 11, 2026. A facility that is not listed here may still be closed, so confirm on the park's site before you go.
- Rock Harbor Visitor Center (visitor center): closed all month (September 20, 2026 to June 8, 2027)
- Windigo Visitor Center (visitor center): closed all month (September 20, 2026 to June 8, 2027)
Things to do at Isle Royale in May
The National Park Service tags 40 Isle Royale activities for spring. Here are 8 of them. Each links to the park's own page for it.
- Attend a Rock Harbor Ranger Program · 20-60 minutes
- Feldtmann Loop Section 2: Hike from Feldtmann Lake to Siskiwit Bay · 1 day
- Greenstone Section 3: Hike from Mount Ojibway to Chickenbone Lake · 1 day
- Harbor to Hills Section 1: Hike from Rock Harbor to Three Mile · 1 day
- Hike the Daisy Farm Trail · 1-3 hours
- Hike to Grace Creek Overlook · 2-4 hours
- Minong Section 3: Hike from Little Todd to North Desor · 1 day
- Portage from Lake LeSage to Lake Richie · 1 day
Frequently Asked Questions
May averages a daytime high near 58°F and an overnight low around 37°F at Isle Royale National Park, with about 3.1 inches of precipitation. These are 1991–2020 NOAA climate normals from the nearest station, about 40 miles from the park, so conditions inside the park can differ, especially at other elevations.
May is very quiet at Isle Royale National Park (about 0.5× the average month). Our best-time score rates it "Good" at 71/100. Our recommended month is September.
The busiest month is August and the quietest is January. May sits at about 0.5× the park's average, or 4% of annual visitation.
A typical May sees about 1,000 recreation visits at Isle Royale National Park, based on National Park Service monthly counts from 1979–2025.
Where to stay near Isle Royale in May
Booking a May trip to Isle Royale National Park? Compare hotels, cabins and vacation rentals near the park with live May availability and prices.
Top-rated places to stay near Isle Royale
Prices for Oct 30–Nov 1, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Visiting Isle Royale in May?
Get crowd forecasts and lodging deals for Isle Royale by email. No spam, unsubscribe anytime.
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.