Sweet spotPeak Jun–Aug. Go in Sep for similar weather.
2018–2023 averages, not a forecast. Wet days estimate days with at least 1 mm of rain or snow using a calibrated ERA5 threshold. Contains modified Copernicus Climate Change Service information. Weather data by Open-Meteo.com (AWS Open Data, CC BY 4.0). Sunny share of daylight does not describe nighttime visibility. Season bars and highlighted months are separate from these weather averages. ERA5 via Open-Meteo AWS Open Data
Isle Royale National Park is a remote island wilderness in the middle of Lake Superior. Weather influences traveling to and from the island, as well as your trip once you arrive. For the most up-to-date weather information, call (906) 482-0984 or email isro_parkinfo@nps.gov prior to your trip.