Deer Island water temp
This data the coastal Deer Island 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 Deer Island
Water temperature in Deer Island today is 63.3°F. Based on our historical data over a period of ten years, the warmest water in this day in the Atlantic Ocean near Deer Island was recorded in 2021 and was 63.9°F, and the coldest was recorded in 2013 at 58.8°F. Sea water temperature in Deer Island is expected to drop to 59.9°F in the next 10 days. September average water temperature in Deer Island is 64°F, the minimum temperature is 58.6°F, and the maximum is 71.8°F.
The swimming season in Deer Island lasts from July to August. During those months, Deer Island water temperature does not drop below 68°F and therefore suitable for comfortable swimming. The average water temperature in Deer Island in winter reaches 41.7°F, in spring 45°F, in summer the average temperature rises to 64.4°F, and in autumn it is 57.4°F.
Deer Island water temperature now
| September 25, 2025 |
|---|
| today temp |
| 63.3°F |
| September 24, 2025 |
|---|
| yesterday temp |
| 63.5°F |
The ocean salinity in Deer Island is 30.58‰, and the average salinity of the World Ocean is 35‰.
Surf Forecast in Deer Island 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 Deer Island. 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 Deer Island. Data in table shown for September 25, 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 |
|---|---|---|---|
| 1' 8" | 1' 7" | 1' 7" | 1' 7" |
| 0.5 m | 0.49 m | 0.47 m | 0.49 m |
| 12-15 h | 15-18 h | 18-21 h | 21-24 h |
|---|---|---|---|
| 1' 8" | 1' 7" | 1' 8" | 1' 9" |
| 0.5 m | 0.49 m | 0.52 m | 0.54 m |
Surf report in Deer Island
Deer Island weather forecast
Current temperature and weather
Data in a table show Deer Island temperature today (September 25, 2025). For more information and forecast for a few days, go to the weather forecast Deer Island.
| 0-3 h | 3-6 h | 6-9 h | 9-12 h |
|---|---|---|---|
 |  | | |
| 63.1°F | 63°F | 63.5°F | 65.8°F |
| 12-15 h | 15-18 h | 18-21 h | 21-24 h |
|---|---|---|---|
 | | | |
| 68°F | 68°F | 69.3°F | 69.3°F |
You may also be interested in other sections of our site for Deer Island: Sunrise and Sunset, Tides
Deer Island water temperature by month
These figures shows the average, minimum and maximum monthly sea temperature in Deer Island. 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 Deer Island 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 | 41.2°F | 36.3°F | 45.9°F | cold |
| Ocean water temperature in Deer Island in January | ||||
| February | 38.5°F | 34.2°F | 42.4°F | cold |
| Ocean water temperature in Deer Island in February | ||||
| March | 39.2°F | 35.4°F | 47.3°F | cold |
| Ocean water temperature in Deer Island in March | ||||
| April | 43.7°F | 36.7°F | 49.5°F | cold |
| Ocean water temperature in Deer Island in April | ||||
| May | 51.8°F | 43.3°F | 63.1°F | cold |
| Ocean water temperature in Deer Island in May | ||||
| June | 59.7°F | 51.4°F | 67.1°F | cold |
| Ocean water temperature in Deer Island in June | ||||
| July | 66.2°F | 59.7°F | 73.9°F | cold |
| Ocean water temperature in Deer Island in July | ||||
| August | 67.3°F | 61.7°F | 73.2°F | cold |
| Ocean water temperature in Deer Island in August | ||||
| September | 64°F | 58.6°F | 71.8°F | cold |
| Ocean water temperature in Deer Island in September | ||||
| October | 57.6°F | 51.6°F | 64.2°F | cold |
| Ocean water temperature in Deer Island in October | ||||
| November | 50.7°F | 45°F | 56.8°F | cold |
| Ocean water temperature in Deer Island in November | ||||
| December | 45.3°F | 39.2°F | 50.4°F | cold |
| Ocean water temperature in Deer Island in December | ||||
Chart monthly average water temperature in Deer Island
