Acadia weather, season by season.
What to expect on Mount Desert Island through the year, what to pack, and why our tours run rain or shine.
Late spring (mid-May to June)
Our season opens in mid-May. Days are cool and often in the 50s and 60s, the crowds are lighter, and the island is greening up. Blackflies can be active from late May into June, so pack a light layer and be ready for changeable weather.
Summer (July and August)
The warmest stretch, with highs near 80 degrees and long, bright days. It is also the busiest, when parking fills early and restaurants and trailheads are at their fullest. Book tours and tables ahead.
Fall (September to mid-October)
Widely considered the best time to visit. Expect crisp, comfortable days for sightseeing, fewer insects, and fall foliage that usually peaks early to mid-October. Our season runs through mid-October.
Off-season (late October into winter)
After we close for the season, the island quiets down and most of Park Loop Road closes to cars from December 1 until mid-April, when the unplowed roads become a route for cross-country skiing and snowshoeing.
Coastal fog, rain, and the summit
Acadia sits where cool ocean meets granite, so fog and mist are part of its character, and the coast at Thunder Hole and the Shore Path can be at its most dramatic in the gray. Rain often moves through quickly rather than settling in for the day. Up on Cadillac Mountain, expect it to be noticeably cooler and windier than in town, even in summer.
What to pack
Layers
A light fleece or jacket even in summer, especially for the summit and the water.
A rain shell
A packable waterproof layer handles the quick coastal showers.
Sturdy shoes
Granite can be uneven and slick when wet; closed-toe shoes with grip are ideal.
Sun and bug protection
Sunscreen and a hat for open overlooks, and bug spray in late spring and early summer.
Does weather affect the tour?
Our tours run rain or shine. You ride in an enclosed, climate-controlled vehicle, so a gray or drizzly day stays comfortable, and a good guide makes the mist part of the story. When conditions call for it, the route can flex to make the most of the day.
Best time to take a tour
Honestly, any day is a good day to ride with us, since we handle the driving for you. Mornings often bring the softest light and the calmest roads. If you are chasing fall color, aim for late September into mid-October, when the island is at its most vivid.
Whatever the forecast, we will show you Acadia.
Comfortable, climate-controlled, and guided by someone who knows the island in every season.