Isle Royale National Park - Climate

Isle Royale National Park by National Parks Service

Lake Superior weather is cool throughout the operating season with dense fog in spring, and in summer sunny with temperatures rarely exceeding 80 degrees Fahrenheit. Thunderstorms and rain occur throughout the season. Weather and rough seas may delay departures to and from the island. Bring plenty of warm clothing, even in August. A jacket is a must for the ferry trip to the island or if boating around the island.