SeasonMapBar Harbor weather in September
United States
September in Bar Harbor: nice, rainy, with clean air — an excellent time to visit.
#4 of 12 months in Bar Harbor · #628 of 1383 destinations to visit in September · comfort 81/100 (tier A)
Updated September 2026 · climate normals from ERA5 reanalysis
Traveller notes on Bar Harbor in September
Other months in Bar Harbor
Bar Harbor's forum calls August warm and sunny by day, mid-to-high 70s°F, cooling into the 60s at night — genuinely pleasant, which is exactly why it's the busiest month of the year here. Regulars' standard packing list covers both shorts and a light jacket for cooler evenings, plus a rain layer just in case, and note the ocean itself stays cold, 55-60°F, even at the height of summer.
Add your own note from Bar Harbor's card on the map.
Bar Harbor climate normals — September
| Daytime high | 19°C / 66°F | 😎 nice |
|---|---|---|
| Nighttime low | 11°C / 52°F | |
| Feels like (high) | 19°C / 66°F | |
| Sea temperature | 18°C / 64°F | 🧊 bracing |
| Rainfall | 93 mm / 3.7 in | 🌧 rainy |
| Rainy days | 7 days | |
| Humidity | 81% | 💦 very humid |
| Dew point | 12°C / 54°F | |
| Sunshine | 8.8 h/day | |
| Daylight | 12.5 h | |
| Wind | 18 km/h / 11 mph | |
| Air quality (US AQI) | 37 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Bar Harbor in September
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
Peak crowdsCruise ship season, Fall foliage, Summer break in United States(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Bar Harbor's weather
Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).
Fair weatherBar Harbor's weather peaks June–August, best around July.
Best weatherFair weatherToughest weather
What's on in Bar Harbor in September
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Season
Cruise ship season
1 May – 31 OctCruise seasonCrowdedShips tender into the harbour from May, and the heaviest calls land in September and October with the leaf cruises. The town's thousand-passenger daily cap survived court only for July and August, so the autumn days are the crowded ones. Source ↗
- Opening
The CAT ferry to Nova Scotia
14 May – 14 Oct · usuallySummer season opensBook earlyThe fast ferry to Yarmouth runs from mid-May to mid-October and takes three and a half hours across the Gulf of Maine. Outside those dates the only way to Nova Scotia is a very long drive. Source ↗
- Nature
Lobster season
15 Jun – 15 Dec · usuallyForaging seasonMost of the Maine catch comes ashore between the summer shed and the end of autumn, and prices at the pounds follow the boats. Late summer soft-shell lobster is cheaper and sweeter than the hard-shell you get flown out of state.
- Nature
Fall foliage
28 Sep – 25 Oct · usuallyAutumn colourCrowdedMount Desert Island turns through the first half of October, later than inland Maine because the sea holds its heat. The colour and the leaf-peeping cruise calls arrive in the same fortnight.
Nearby, and something's on
Within 300 km of Bar Harbor — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Bar Harbor?
Bar Harbor in September — FAQ
- Is September a good time to visit Bar Harbor?
- September in Bar Harbor: nice, rainy, with clean air — an excellent time to visit. It ranks #4 of 12 months for Bar Harbor on SeasonMap's comfort score (81/100).
- What is the weather like in Bar Harbor in September?
- In September, Bar Harbor averages a daily high of 19.1°C and a low of 11.3°C, with about 93.1 mm of rain over roughly 6.6 rainy days.
- What is the air quality in Bar Harbor in September?
- Bar Harbor has a mean US Air Quality Index of about 37 in September.
Other months in Bar Harbor
Compare Bar Harbor in September
Warmer or cooler than Bar Harbor in September
Similar destinations in North America — September
Within 300 km: Acadia National Park's Fall foliage around 28 Sep – 25 Oct.