Late summer · Weather & things to do
Portland, Maine in August
Portland, Maine's warmest month brings highs averaging 70°F (21°C), lows of 64°F (18°C) and about 3.7 in (94 mm) of rain.
It scores 74/100 for comfort, 3rd of 12, which makes it a solid shoulder-season month.
- Avg high
- 70°F (21°C)
- Avg low
- 64°F (18°C)
- Rain
- 3.7 in (94 mm)
- Humidity
- 86%
- Cloud cover
- 52%
- Daylight
- ~13 h 48 min
- Comfort score
- 74/100 · Good
What August feels like
Warm afternoons near 70°F (21°C) make long days outdoors easy.
Nights cool to an average low of 64°F (18°C).
Some rain is likely, about 3.7 in (94 mm) in the month, so pack for a shower or two.
Plan around August
August is shoulder season: good weather, a step below the best months (September).
- First warm month: highs reach 70°F, up from 69°F in July.
- Last warm month for a while: September highs fall to 65°F.
- Comfort holds steady from July (72 → 74/100).
- August sits inside the May – Oct window our Boston to Portland route recommends.
What to pack for August
- Light, breathable clotheshighs average 70°F
- Sunscreen, sunglasses and a hathigh UV on clear days
- Packable rain jacket or umbrellaabout 3.7 in of rain
- Comfortable walking shoesmost places below are best reached on foot or with short walks
What to do in Portland, Maine in August
With conditions on your side, the picks below favor time outside.
Portland Head Light
Maine's oldest lighthouse (1791) on cliffs in Fort Williams Park.
Why now August scores 74/100 for comfort, good conditions for being outside.
Casco Bay Lines
Ferries to Peaks Island and the outer islands for a cheap harbor cruise.
Why now Our curated notes say it's best summer.
Duckfat
Small sandwich shop famous for fries cooked in duck fat.
Eventide Oyster Co.
Oyster bar known for its brown-butter lobster roll on a steamed bun.
Eastern Promenade
Hilltop park and trail with views over Casco Bay and its islands.
Why now Highs near 70°F and 3.7 in of monthly rain make this an easy outdoor pick.
Nearby in August
- Portsmouth in August~48 mi · highs 74°F, 3.7 in rain · 2°C (4°F) warmer by day, about as wet
- Maine in August~51 mi · highs 78°F, 4.3 in rain · 5°C (8°F) warmer by day, about as wet
- White Mountains in August~67 mi · highs 56°F, 4.4 in rain · 8°C (14°F) cooler by day, wetter
- New Hampshire in August~73 mi · highs 80°F, 3.9 in rain · 6°C (10°F) warmer by day, about as wet
NASA POWER 2001–2025 monthly averages on a ~50 km grid. Comfort scores weigh temperature, rain, humidity and cloud: see how we score each month. Check a forecast before you go.
Portland, Maine in August: quick answers
Is August a good time to visit Portland, Maine?
It's a good shoulder-season choice, scoring 74/100 against a best of 87 in September. Expect highs of 70°F (21°C) and 3.7 in (94 mm) of rain. August is inside the May – Oct window our Boston to Portland route recommends.
How hot is Portland, Maine in August?
Average highs are 70°F (21°C) and average lows 64°F (18°C), making it the warmest month by daytime highs.
Does it rain a lot in Portland, Maine in August?
Some: about 3.7 in (94 mm) of rain falls across August on average, the driest month of the year. The annual total is about 53.7 in (1363 mm).
What should I pack for Portland, Maine in August?
Bring light, breathable clothes (highs average 70°F), sunscreen, sunglasses and a hat (high UV on clear days), packable rain jacket or umbrella (about 3.7 in of rain) and comfortable walking shoes (most places below are best reached on foot or with short walks).
More on Portland, Maine
Routes in season in August
- Boston to Portland May – Oct
Planning Portland, Maine in August?
Plan it together in TripsCircle: one itinerary, one shared packing list and costs split as you go.