Weather Forecast and Radar for Isle Royale National Park

Routes Running Nearby to Isle Royale National Park

• The I-35 runs south from Duluth, MN, about 150 miles southwest of Isle Royale National Park.

Weather in Isle Royale National Park

In Isle Royale National Park, the summers are comfortable, the winters are frigid and snowy, and it is partly cloudy year round. Over the course of the year, the temperature typically varies from -1°F to 76°F and is rarely below -21°F or above 85°F.

The warm season lasts for 3.5 months, from May to September, with an average daily high temperature above 64°F. The hottest month of the year in Isle Royale National Park is July, with an average high of 75°F and low of 54°F.

The cold season lasts for 3 months, from November to March, with an average daily high temperature below 29°F. The coldest month of the year in Isle Royale National Park is January, with an average low of -0°F and high of 18°F.

Isle Royale National Park is the only national park that is closed in the off season. This is due to bitterly cold weather experienced outside of the summer. Lake Superior weather is cool even in summer, causing often dense fog. The lake’s water temperature rarely exceeds 52°F. Thunderstorms and rain occur throughout the summer, causing frequent and major changes in wind. Because of this, rough seas can be an issue on Lake Superior at any time.

Fast Facts About Isle Royale National Park

The park was established in 1940.

Major Cities Nearby Isle Royale National Park

• Thunder Bay, Ontario, Canada (roughly 25 miles to the north)
• Duluth, Minnesota (roughly 150 miles to the southwest)
• Detroit, Michigan (roughly 496 miles to the southeast)

This map shows the current & 7-day weather forecast, weather alerts, and weather radar for Isle Royale National Park.