Portland, Maine weather in August
Temperature, sea and sunshine in August: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in August
Fair
Best time to visit: July – August
What is the weather like in Portland, Maine in August?
In August, Portland, Maine is warm: daytime highs average 24 °C, and nights cool down to about 18 °C. The sea averages 17.7 °C – bracing, so a wetsuit helps for longer swims. The sun shines for around 8 hours a day. Rain falls on about 9 days, adding up to 73 mm. All in all, August is a so-so month for a holiday in Portland, Maine.
August compared
How the weather changes from July to September. Tap a month to open it.
| JulyJul | AugustAug | SeptemberSep | |
|---|---|---|---|
| Score | 58 | 58 | 33 |
| Day | 24° | 24° | 20° |
| Night | 18° | 18° | 14° |
| Sea | 17° | 18° | 16° |
| Sun | 8 h | 8 h | 7 h |
| Rain days | 10 | 9 | 8 |
More details for August
- Daylight
- 14 h 2 min05:45 – 19:47
- UV index
- 8 · very highclear sky, noon (estimate)All months
- Muggy days
- 9 daysdew point 18 °C or moreAll months
- Wind
- 15 km/haverage daily peakAll months
- Cloud cover
- 54 %on averageAll months
- Hot days
- 0 days30 °C or moreAll months
- Snow days
- 0 days1 cm or more of fresh snowAll months
- Time zone
- UTC−4America/New_York
How the score comes together
- Temperatureweight 35 %77 %
- Seaweight 25 %10 %
- Sunshineweight 20 %75 %
- Few rainy daysweight 20 %66 %
Each factor is rated from 0 to 100 % and weighted for the travel style “Sun, sea & sand”.
What to pack in August
- Wetsuit for longer swims
- Sunscreen
- Sunglasses & sun hat
- Rain jacket or umbrella
Portland, Maine in August: quick answers
Is Portland, Maine hot in August?
Warm rather than hot: in August, daytime highs in Portland, Maine average 24 °C and nights cool to about 18 °C.
Can you swim in Portland, Maine in August?
Only if you don't mind cold water: in August the sea averages just 17.7 °C. Comfortable swimming temperatures are not reached at any time of year.
Does it rain much in Portland, Maine in August?
Rain falls on about 9 days, adding up to 73 mm.
Portland, Maine month by month
The whole year in Portland, MaineAll destinations: USAWhere to go in AugustSea temperature in August
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences