Acadia National Park weather in September
September in Acadia National Park: nice, rainy, with clean air — an excellent time to visit.
#5 of 12 months in Acadia National Park · #295 of 604 destinations to visit in September · comfort 80/100 (tier A)
Updated June 2026 · climate normals from ERA5 reanalysis
Acadia National Park climate normals — September
| Daytime high | 18°C / 64°F | 😎 nice |
|---|---|---|
| Nighttime low | 13°C / 56°F | |
| Feels like (high) | 17°C / 63°F | |
| Rainfall | 114 mm / 4.5 in | 🌧 rainy |
| Rainy days | 9 days | |
| Humidity | 83% | 💦 very humid |
| Dew point | 13°C / 55°F | |
| Sunshine | 8.6 h/day | |
| Daylight | 12.5 h | |
| Wind | 19 km/h / 12 mph | |
| Air quality (US AQI) | 37 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Where is Acadia National Park?
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Acadia National Park in September — FAQ
- Is September a good time to visit Acadia National Park?
- September in Acadia National Park: nice, rainy, with clean air — an excellent time to visit. It ranks #5 of 12 months for Acadia National Park on SeasonMap's comfort score (80/100).
- What is the weather like in Acadia National Park in September?
- In September, Acadia National Park averages a daily high of 17.5°C and a low of 13.4°C, with about 113.7 mm of rain over roughly 9 rainy days.
- What is the air quality in Acadia National Park in September?
- Acadia National Park has a mean US Air Quality Index of about 37 in September.