September in Acadia National Park is a best window month: highs around 71°F, lows around 50°F. Crowds: busy — #3 busiest of the park's 12 months. The sweet spot: warm days, thinner crowds, everything open. The editorial best window here is September–October. You get about 12h 31m of daylight. To finish Ocean Path (1h 30m) before dark, leave the trailhead by about 5:13 PM.
Month data reviewed · how we check this
| Verdict | Best window The editorial pick — weather, access and experience line up. |
|---|---|
| Temps °F | 71° high / 50° low |
| Crowds | busy · #3 busiest of the park's 12 months |
| What September is like | The sweet spot: warm days, thinner crowds, everything open |
| Best window (whole year) | September–October |
| Peak crowds (whole year) | Jul–Aug |
CROWDS: RELATIVE SEASONALITY FROM NPS VISITATION STATISTICS · TEMPS: APPROXIMATE NOAA NORMALS AT MAIN VISITOR ELEVATION — HIGH COUNTRY RUNS 10–20°F COLDER
DAYLIGHT ON SEPTEMBER 15 · LOCAL PARK TIME (EDT)COMPUTED FROM THE PARK'S OWN COORDINATES FOR THE 15TH — THE MIDDLE OF THE MONTH STANDS FOR IT, AS IT DOES FOR CLIMATE NORMALS. WITHIN A MONTH THESE TIMES SHIFT BY UP TO AN HOUR
LEAVE THE TRAILHEAD BY — TO FINISH BEFORE DARK ON SEPTEMBER 15WALKING TIMES ESTIMATED FROM EACH TRAIL'S MEASURED DISTANCE AND ELEVATION GAIN — A PLANNING FIGURE, NOT A PACE. ADD YOUR OWN MARGIN FOR PHOTOS, REST AND CROWDS. WATER AT THE COOL-WEATHER RATE, BECAUSE THIS MONTH AVERAGES 71°F. TRAILS WE HAVE NOT MEASURED ARE LEFT OUT RATHER THAN GUESSED
WHAT SEPTEMBER ASKS OF YOU HEREAcadia National Park in October — Best window, highs around 59°F, crowds: busy (fall foliage peaks early-to-mid october; weekends busy).
Our verdict for September is "Best window". The editorial pick — weather, access and experience line up. Expect highs around 71°F and lows around 50°F, with crowds at the "busy" level. Temperatures are approximate NOAA normals at the main visitor elevation; crowd levels follow published NPS visitation statistics.
Across the full 12-month review, the best window is September–October, and the peak-crowd months are Jul–Aug. September itself we rate "Best window".
About 12h 31m on September 15: the sun rises around 6:12 AM and sets around 6:43 PM local park time (EDT). Computed from the park's own coordinates, so it is the light you actually get at the trailhead, not the nearest city's.
Ocean Path takes about 1h 30m of walking, so on September 15 you would need to leave the trailhead by about 5:13 PM to finish before dark — the sun sets around 6:43 PM local park time (EDT). Walking times are estimated from each trail's measured distance and elevation gain, so treat them as a planning figure and add your own margin for photos, rest and crowds.
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