South Portland water temp
This data the coastal South Portland ocean water temperature today, tomorrow and the upcoming days. Besides, you can also get information about the weather and surf forecast, as well as the data on sunrise / sunset and moonrise / moonset at a given point on any given day.
Current ocean temperature in South Portland
Water temperature in South Portland today is 63.3°F. Based on our historical data over a period of ten years, the warmest water in this day in South Portland was recorded in 2018 and was 67.5°F, and the coldest was recorded in 2017 at 58.8°F. Sea water temperature in South Portland is expected to drop to 60.8°F in the next 10 days. September average water temperature in South Portland is 60.8°F, the minimum temperature is 56.3°F, and the maximum is 68°F.
Throughout the year, the water temperature in South Portland does not rise above 68°F and therefore is not suitable for comfortable swimming. But on some days of September, the water temperature warms up to 68°F and above. The average water temperature in South Portland in winter reaches 41.7°F, in spring 43.2°F, in summer the average temperature rises to 61.3°F, and in autumn it is 55.4°F.
South Portland water temperature now
| September 5, 2025 |
|---|
| today temp |
| 63.3°F |
| September 4, 2025 |
|---|
| yesterday temp |
| 62.8°F |
The ocean salinity in South Portland is 30.45‰, and the average salinity of the World Ocean is 35‰.
Surf Forecast in South Portland for today
Another important indicators for a comfortable holiday on the beach are the presence and height of the waves, as well as the speed and direction of the wind. Please find below data on the swell size for South Portland. We calculate the swell size based on the mean wave height (trough to crest) of each third highest wave. For more information on surf forecasts for the next ten days, please visit sea state forecast South Portland. Data in table shown for September 5, 2025, time in GMT 0 format (you can change the time zone on the sea state forecast page)
| 0-3 h | 3-6 h | 6-9 h | 9-12 h |
|---|---|---|---|
| 2' 11" | 2' 11" | 2' 9" | 2' 10" |
| 0.88 m | 0.89 m | 0.84 m | 0.87 m |
| 12-15 h | 15-18 h | 18-21 h | 21-24 h |
|---|---|---|---|
| 2' 11" | 2' 10" | 3' 1" | 4' 0" |
| 0.88 m | 0.87 m | 0.95 m | 1.21 m |
Surf report in South Portland
South Portland weather forecast
Current temperature and weather
Data in a table show South Portland temperature today (September 5, 2025). For more information and forecast for a few days, go to the weather forecast South Portland.
| 0-3 h | 3-6 h | 6-9 h | 9-12 h |
|---|---|---|---|
 | | | |
| 63.7°F | 62.8°F | 63.5°F | 64.9°F |
| 12-15 h | 15-18 h | 18-21 h | 21-24 h |
|---|---|---|---|
 | | | |
| 67.6°F | 68.2°F | 67.6°F | 66.4°F |
You may also be interested in other sections of our site for South Portland: Sunrise and Sunset, Tides
South Portland water temperature by month
These figures shows the average, minimum and maximum monthly sea temperature in South Portland. In addition to the table values, the graph below displays of changes average surface temperature during the year. Values are calculated based on the data over the past 10 years. Using them, you can check the water temperature in South Portland on any day of this period that interests you. Click on the month link and you will see a table for each day, or alternatively you can view the temperature curve of the month and select 2 different years you want to compare, either in a table or as a curve
| Month | Avr | Min | Max | |
|---|---|---|---|---|
| January | 41.5°F | 36.7°F | 47.7°F | cold |
| Ocean water temperature in South Portland in January | ||||
| February | 38.7°F | 34.3°F | 42.3°F | cold |
| Ocean water temperature in South Portland in February | ||||
| March | 38.7°F | 34.7°F | 45.5°F | cold |
| Ocean water temperature in South Portland in March | ||||
| April | 42.1°F | 36.7°F | 49.6°F | cold |
| Ocean water temperature in South Portland in April | ||||
| May | 48.9°F | 42.6°F | 59.7°F | cold |
| Ocean water temperature in South Portland in May | ||||
| June | 56.7°F | 49.3°F | 65.1°F | cold |
| Ocean water temperature in South Portland in June | ||||
| July | 62.8°F | 54.3°F | 69.1°F | cold |
| Ocean water temperature in South Portland in July | ||||
| August | 64.4°F | 59.2°F | 69.8°F | cold |
| Ocean water temperature in South Portland in August | ||||
| September | 60.8°F | 56.3°F | 68°F | cold |
| Ocean water temperature in South Portland in September | ||||
| October | 55.6°F | 50.2°F | 61.5°F | cold |
| Ocean water temperature in South Portland in October | ||||
| November | 49.8°F | 44.8°F | 55.4°F | cold |
| Ocean water temperature in South Portland in November | ||||
| December | 45°F | 39.9°F | 51.1°F | cold |
| Ocean water temperature in South Portland in December | ||||
Chart monthly average water temperature in South Portland
