Dennis water temp
This data the coastal Dennis 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 Dennis
Water temperature in Dennis today is 66.7°F. Based on our historical data over a period of ten years, the warmest water in this day in the Cape Cod Bay near Dennis was recorded in 2021 and was 69.3°F, and the coldest was recorded in 2013 at 61.9°F. Sea water temperature in Dennis is expected to drop to 62.1°F in the next 10 days. September average water temperature in Dennis is 66.4°F, the minimum temperature is 60.1°F, and the maximum is 73.6°F.
The swimming season in Dennis lasts from July to September. During those months, Dennis water temperature does not drop below 68°F and therefore suitable for comfortable swimming. The average water temperature in Dennis in winter reaches 40.6°F, in spring 45.3°F, in summer the average temperature rises to 66.9°F, and in autumn it is 59°F.
Dennis water temperature now
| September 25, 2025 |
|---|
| today temp |
| 66.7°F |
| September 24, 2025 |
|---|
| yesterday temp |
| 65.5°F |
The ocean salinity in Dennis is 31.17‰, and the average salinity of the World Ocean is 35‰.
Surf Forecast in Dennis 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 Dennis. 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 Dennis. 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' 5" | 1' 4" | 1' 3" | 1' 3" |
| 0.43 m | 0.41 m | 0.38 m | 0.37 m |
| 12-15 h | 15-18 h | 18-21 h | 21-24 h |
|---|---|---|---|
| 1' 5" | 1' 7" | 1' 9" | 2' 0" |
| 0.43 m | 0.48 m | 0.54 m | 0.6 m |
Surf report in Dennis
Dennis weather forecast
Current temperature and weather
Data in a table show Dennis temperature today (September 25, 2025). For more information and forecast for a few days, go to the weather forecast Dennis.
| 0-3 h | 3-6 h | 6-9 h | 9-12 h |
|---|---|---|---|
 | | | |
| 63.5°F | 63.9°F | 64.4°F | 66.7°F |
| 12-15 h | 15-18 h | 18-21 h | 21-24 h |
|---|---|---|---|
 | | | |
| 68.7°F | 69.3°F | 69.6°F | 69.6°F |
You may also be interested in other sections of our site for Dennis: Sunrise and Sunset, Tides
Dennis water temperature by month
These figures shows the average, minimum and maximum monthly sea temperature in Dennis. 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 Dennis 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 | 39.7°F | 33.1°F | 46.4°F | cold |
| Ocean water temperature in Dennis in January | ||||
| February | 37.2°F | 30.9°F | 42.1°F | cold |
| Ocean water temperature in Dennis in February | ||||
| March | 39°F | 31.8°F | 46.4°F | cold |
| Ocean water temperature in Dennis in March | ||||
| April | 44.4°F | 36.3°F | 52°F | cold |
| Ocean water temperature in Dennis in April | ||||
| May | 52.5°F | 45°F | 62.6°F | cold |
| Ocean water temperature in Dennis in May | ||||
| June | 61.5°F | 52.5°F | 71.8°F | cold |
| Ocean water temperature in Dennis in June | ||||
| July | 69.1°F | 60.8°F | 77.5°F | warm |
| Ocean water temperature in Dennis in July | ||||
| August | 70.2°F | 63.7°F | 78.1°F | warm |
| Ocean water temperature in Dennis in August | ||||
| September | 66.4°F | 60.1°F | 73.6°F | cold |
| Ocean water temperature in Dennis in September | ||||
| October | 59.4°F | 52.5°F | 67.1°F | cold |
| Ocean water temperature in Dennis in October | ||||
| November | 51.3°F | 43.2°F | 60.6°F | cold |
| Ocean water temperature in Dennis in November | ||||
| December | 44.8°F | 37.6°F | 51.1°F | cold |
| Ocean water temperature in Dennis in December | ||||
Chart monthly average water temperature in Dennis
