South Portland (ME) Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit South Portland.
Climate overview of South Portland
The climate in South Portland, Maine, United States of America, is marked by large temperature swings across the seasons, ranging from 26°C (79°F) in July to 0°C (32°F) in January.
The city receives considerable rain/snowfall, with around 1415 mm (56 in) annually. June is the wettest month. It has warm summers and very cold winters. July is the sunniest month, averaging 9.3 hours of sunshine per day.
South Portland Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in South Portland - and find the best time to visit.
Monthly Temperature in South Portland
In South Portland, temperatures differ significantly between summer and winter months. Typically, average maximum daytime temperatures range from a comfortable 26°C (79°F) in July to a very cold 0°C (32°F) in the coolest month, January.
Nights vary from 17°C (63°F) in July to around -9°C (16°F) during the colder months.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in South Portland
South Portland experiences significant rain/snowfall throughout the year, averaging 1415 mm (56 in) of precipitation annually. South Portland offers a pleasant mix of wetter and slightly drier months. The difference in precipitation between the wettest month June (156 mm (6.1 in)) and the driest month January (88 mm (3.5 in)) is not too significant. For more details, please visit our South Portland Precipitation page.
The mean monthly precipitation over the year, including rain, hail, and snow
The average number of days each month with precipitation
Sunshine Hours in South Portland
For those who appreciate different seasons, South Portland serves as an ideal destination. Expect longer, more sun-filled days in July with an average of 9.3 hours of sunshine daily, and embrace the darker days in December, offering only 4.7 hours of daily sunlight.
Visit our detailed sunshine hours page for more information.
Monthly hours of sunshine
Daily hours of sunshine
Daily percentage of sunshine
Water Temperature in South Portland
The mean water temperature over the year ranges from 3°C (37°F) in March to 18°C (64°F) in August.
Water temperature over the year
Humidity in South Portland by Month
The relative humidity is high throughout the year in South Portland.
The city experiences its highest humidity in September, reaching 77%. In February, the humidity drops to its lowest level at 65%. What does this mean? Read our detailed page on humidity levels for further details.
Relative humidity over the year
Best Time to Visit South Portland
Monthly ratings reflect general weather comfort, based on daytime temperature and rainfall. Swimming and winter conditions are highlighted separately where relevant.
- Best overall: June, July, August and September
- Warmest weather: July and August
- Most sunshine: July and August
- Warmest water temperature: August, although the water may still feel cool.
- Seasonal pattern: Warm summers and very cold winters
- Coldest conditions: January, with freezing nights around -9°C (16°F).
Frequently asked questions about the climate in South Portland
What is the best time to visit South Portland?
June, July, August and September typically offer the most optimal weather in South Portland. In contrast, January, February, March, April, November and December tend to have less optimal conditions. South Portland has warm summers and very cold winters.
What temperatures can I expect in South Portland?
Daytime highs range from 0°C (32°F) in January to 26°C (79°F) in July. Nighttime lows range from -9°C (16°F) to 17°C (63°F). Temperatures vary considerably through the year.
How much rain does South Portland get?
Annual rainfall is around 1415 mm (56 in). June is the wettest month with 156 mm (6.1 in), while January is the driest with 88 mm (3.5 in).
How sunny is South Portland?
South Portland receives around 2,497 hours of sunshine per year. July is the sunniest month with 278 hours, while December is the cloudiest with just 140 hours. Overall, South Portland enjoys abundant sunshine.
South Portland 3-Day Forecast
South Portland (ME) 3-Day Forecast
South Portland on the map
South Portland is highlighted - select any city to see its climate.
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