‹ Portland, Maine weather by month
Typical September weather
Portland, Maine
Maine · September
71° days
52° nights
about 5 rainy days · 12½ hours of daylight · ocean 62°
What to pack
- Light jacket
What September feels like
The crowds go home after Labor Day while the water holds nearly all of its summer warmth, and the afternoons are the clearest of the year. Locals get their restaurant reservations back and the Old Port becomes a place you'd want to live rather than visit.
Expect about 5 days with real rain — enough to notice, not enough to plan around. Humidity stays comfortable; the air never feels heavy.
Can you swim?
The ocean runs about 62° — cold — a quick dip takes resolve.
The numbers
| Typical high | 71° |
|---|---|
| Typical low | 52° |
| Days with real rain | 5 |
| Total rain | 3.8 in |
| Humidity | comfortable |
| Water temperature | 62° |
| Sunrise / sunset (mid-month) | 6:20 am / 6:51 pm |