September is one of the best months to visit Maine. Summer crowds thin after Labor Day, the water is still swimmable early in the month, days are warm and nights are cool, and fall color starts in the north late in the month. Weather figures below are from the National Weather Service.
Visiting earlier in the year? See Maine in Summer.
What Is the Weather Like in Maine in September?
Using the National Weather Service’s 1991-2020 normals for Portland, daytime highs fall from about 76°F on September 1 to 72°F by mid-month and 66°F by September 30. Overnight lows drop from about 57°F to 53°F to 47°F. Portland averages roughly 3.8 inches of rain for the month.
Inland and northern Maine run cooler than the coast, and the ocean stays cold in every month. Bring layers for evenings and a rain jacket.
How Crowded Is Maine in September?
Noticeably less than July and August, especially after Labor Day. Lodging is easier to find and often cheaper on weekdays, though popular places like Acadia and the coastal towns still fill up on weekends as foliage season approaches. Our guide to the best time to visit Maine compares all the seasons.
Is Fall Foliage Visible in September?
Only the beginning. Color usually starts in northern Maine and at higher elevations toward the end of the month, while most of the state peaks in October. If foliage is your goal, see our Maine fall foliage guide and the foliage timing tracker, or plan for Maine in October.
Fairs, Festivals, and Events in September
Late September is fair season. The Common Ground Country Fair in Unity is held in late September (September 25-27 in 2026), and the Cumberland Fair begins at the end of the month. Harvest festivals, farmers’ markets, and lobster and food events fill the weekends. See our Maine events calendar for current dates and official links.
What Is Open and What Closes in September?
Most attractions, boat tours, and restaurants stay open through September and into October, though some reduce days or hours after Labor Day, so call ahead. Most state park campgrounds are still open. See our guide to state park camping reservations and our list of Maine campgrounds.
Best Things to Do in Maine in September
- Hike. Cooler weather and fewer bugs make it a great month. See Baxter State Park and Bar Harbor and Acadia.
- Visit the coast while the crowds are smaller. Try Camden or Belfast.
- Go to a fair or harvest event. Check the events calendar.
Maine in September FAQ
Is September a good time to visit Maine?
Yes. Many people consider it the best month: warm days, cool nights, fewer crowds than summer, and the start of fall color in the north.
Can you swim in Maine in September?
Lakes and ponds are often comfortable early in the month. The ocean is cold year-round, and it cools further as the month goes on.
Is it too early for fall foliage in September?
For most of Maine, yes. Northern and high-elevation areas start to turn late in the month, and the broader peak usually comes in October.
What should I pack for Maine in September?
Layers, a light jacket or sweater for evenings, a rain jacket, and sturdy shoes. Add swimwear if you plan to visit a lake early in the month.
Weather figures are National Weather Service 1991-2020 normals for Portland. Fair dates and seasonal schedules change each year, so confirm details with the organizer before you go.