Isle Royale's Short April-to-October Season

From November 1 through April 15, the island is closed to all visitors. Aircraft landings and other public use are not allowed during that winter stretch. The closure also reaches about four and a half miles out into Lake Superior, and the park headquarters moves to Houghton, Michigan, for the winter.

Getting to the island during the open months depends on the ferries and seaplane, which carry the public from mid-May through September. Each provider publishes its own timetable, so look up the current schedule on its website before you book. The park's summer headquarters is located on Mott Island.

Spring and fall are shoulder seasons, and they ask for more planning than midsummer does. In April, May, and early June, and again in September and October, you will be largely on your own, since staffed services and rescue help are scarce or absent. Snow and ice can hang on trails, campgrounds, and shorelines into late May, and on the north shore and northeast end they may last into summer.

Conditions here are hard to predict. The cold lake tempers the island's temperatures, keeping summers cool and nights chilly even in August, when they can drop below 50 degrees. Gale-force winds and high waves show up often, and a weather system may linger for several days. Rain is hard to avoid, since a multi-day summer stay without at least some rain is unusual. Autumn days can feel mild, but the nights get cold, and snow, ice, and freezing spray may appear along shorelines in September and October.

Before you leave home, check The Greenstone newspaper for current conditions, along with the Isle Royale recreational forecast and the Isle Royale marine forecast. Dress in layers and bring waterproof gear on every outing.