Best Time to Visit Isle Royale National Park
The best months to visit Isle Royale National Park are May, September and October — computed from official NPS visitation (2021–2025 average), NOAA weather normals and daylight. August is the crowd peak (8,468 monthly visits); January is quietest at under 1% of peak.
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- Boat Fuel Unavailable (Information)
- Island Mine Campground Stream Low (Caution)
- Tent Camping Closed at Multiple East End Campgrounds (Park Closure)
Monthly crowd curve
Average monthly recreation visits, 2021–2025 (NPS Visitor Use Statistics). Amber bar = current month.
Isle Royale month by month
| Month | Verdict | Avg visits | % of peak | High / Low | Precip | Daylight |
|---|---|---|---|---|---|---|
| January | Harsh season | 0 | 0% | 20°F / 1°F | 1.4″ | 8.8h |
| February | Harsh season | 0 | 0% | 24°F / 2°F | 1.0″ | 10.2h |
| March | Shoulder | 0 | 0% | 34°F / 13°F | 1.3″ | 11.8h |
| April | Shoulder | 56 | 1% | 45°F / 26°F | 2.8″ | 13.6h |
| May | Best window | 1,404 | 17% | 58°F / 37°F | 3.1″ | 15.2h |
| June | Shoulder | 5,755 | 68% | 68°F / 46°F | 3.6″ | 16h |
| July | Peak crowds | 8,430 | 100% | 74°F / 52°F | 3.4″ | 15.7h |
| August | Peak crowds | 8,468 | 100% | 73°F / 52°F | 3.0″ | 14.3h |
| September | Best window | 3,309 | 39% | 65°F / 44°F | 3.1″ | 12.6h |
| October | Best window | 210 | 2% | 51°F / 33°F | 3.4″ | 10.9h |
| November | Shoulder | 0 | 0% | 38°F / 22°F | 2.6″ | 9.3h |
| December | Harsh season | 0 | 0% | 26°F / 9°F | 1.7″ | 8.4h |
Crowds: NPS Visitor Use Statistics, mean of 2021–2025 (2020 excluded as a COVID-19 anomaly). Weather: NOAA 1991–2020 monthly normals, station GRAND PORTAGE, MN US (36 mi from park coordinates). Daylight: computed for the 15th of each month at the park's location. Methodology.
How many people visit Isle Royale each year
Isle Royale National Park had 29,091 recreation visits in 2025, 1% more than 2024 (NPS Visitor Use Statistics). The busiest year since 2015 was 2025, with 29,091. Over 2021–2025 it averaged 27,632 visits a year, which makes it the 5th least-visited of the 63 national parks.
| Year | Recreation visits | vs. year before |
|---|---|---|
| 2025 | 29,091 | +1% |
| 2024 | 28,806 | −1% |
| 2023 | 28,965 | +14% |
| 2022 | 25,454 | −2% |
| 2021 | 25,844 | +298% |
| 2020 | 6,493 | −75% |
| 2019 | 26,410 | +2% |
| 2018 | 25,798 | −9% |
| 2017 | 28,196 | +13% |
| 2016 | 24,966 | +34% |
| 2015 | 18,684 | — |
Calendar-year recreation visits as published by NPS Visitor Use Statistics. 2020 is shown here but left out of the monthly averages above, because the COVID-19 pandemic makes it unrepresentative. See how every park compares: all 63 parks ranked by visits.
What to pack for Isle Royale in May
Computed from May's weather normals — Isle Royale's best month above. Visiting another month? Each month page has its own weather-computed list.
- Warm mid-layer (fleece or light puffy) — mornings average 37°F
- Packable rain jacket — 3.1″ of precipitation is normal this month
- Sturdy broken-in footwear, navigation and a basic first-aid kit — every park, every month
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Common questions
What is the best month to visit Isle Royale?
May, September and October rank best for Isle Royale on VisitWhen's computed score — the strongest balance of low crowds (NPS data), comfortable weather (NOAA normals) and daylight, among months when the park’s headline access is typically open.
What is the most crowded month at Isle Royale?
August: an average of 8,468 recreation visits (NPS, 2021–2025). The quietest is January, at under 1% of the August peak.
When is Isle Royale least crowded with decent conditions?
October, at 2% of the August peak (210 average visits). January is quieter still, but headline access is typically closed then.
How many people visit Isle Royale per year?
Isle Royale National Park had 29,091 recreation visits in 2025, 1% more than 2024 (NPS Visitor Use Statistics). The busiest year since 2015 was 2025, with 29,091. Over 2021–2025 it averaged 27,632 visits a year.
What is the weather like at Isle Royale through the year?
The warmest month is July, with average highs of 74°F. The coldest nights come in January, averaging 1°F. The wettest month is June, with 3.6″ of precipitation. (NOAA 1991–2020 normals, GRAND PORTAGE, MN US station.)
Is Isle Royale open all year?
Isle Royale is the only national park that fully closes: no visitor access Nov 1 – mid-April. Ferries/seaplanes run roughly May–October. Dates shift with snow and weather each year, so check the park's current NPS conditions before you go.
Dive into a month
Comparing parks for the same trip? See how Isle Royale ranks against all 63 parks in May, September and October.
Last verified 2026-09-24 · all parks