Groton water temp
This data the coastal Groton 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 Groton
Water temperature in Groton today is 68.5°F. Based on our historical data over a period of ten years, the warmest water in this day in Groton was recorded in 2021 and was 70.9°F, and the coldest was recorded in 2024 at 64.6°F. Sea water temperature in Groton is expected to drop to 65.7°F in the next 10 days. September average water temperature in Groton is 68.4°F, the minimum temperature is 63.5°F, and the maximum is 73.8°F.
The swimming season in Groton lasts from July to September. During those months, Groton water temperature does not drop below 68°F and therefore suitable for comfortable swimming. The average water temperature in Groton in winter reaches 43°F, in spring 45.3°F, in summer the average temperature rises to 66.2°F, and in autumn it is 62.4°F.
Groton water temperature now
| September 25, 2025 |
|---|
| today temp |
| 68.5°F |
| September 24, 2025 |
|---|
| yesterday temp |
| 68.4°F |
The ocean salinity in Groton is 28.51‰, and the average salinity of the World Ocean is 35‰.
Surf Forecast in Groton 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 Groton. 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 Groton. 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' 4" | 1' 4" | 1' 3" | 1' 8" |
| 0.41 m | 0.41 m | 0.39 m | 0.5 m |
| 12-15 h | 15-18 h | 18-21 h | 21-24 h |
|---|---|---|---|
| 1' 10" | 1' 11" | 1' 11" | 2' 4" |
| 0.56 m | 0.58 m | 0.58 m | 0.71 m |
Surf report in Groton
Groton weather forecast
Current temperature and weather
Data in a table show Groton temperature today (September 25, 2025). For more information and forecast for a few days, go to the weather forecast Groton.
| 0-3 h | 3-6 h | 6-9 h | 9-12 h |
|---|---|---|---|
 |  | |  |
| 66.2°F | 66.2°F | 67.3°F | 69.8°F |
| 12-15 h | 15-18 h | 18-21 h | 21-24 h |
|---|---|---|---|
| | | |
| 71.2°F | 71.1°F | 71.1°F | 70.2°F |
You may also be interested in other sections of our site for Groton: Sunrise and Sunset, Tides
Groton water temperature by month
These figures shows the average, minimum and maximum monthly sea temperature in Groton. 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 Groton 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 | 41.9°F | 36.7°F | 49.6°F | cold |
| Ocean water temperature in Groton in January | ||||
| February | 39°F | 32.4°F | 43.7°F | cold |
| Ocean water temperature in Groton in February | ||||
| March | 39.9°F | 32.7°F | 51.3°F | cold |
| Ocean water temperature in Groton in March | ||||
| April | 44.4°F | 36.3°F | 51.6°F | cold |
| Ocean water temperature in Groton in April | ||||
| May | 51.6°F | 45.3°F | 62.8°F | cold |
| Ocean water temperature in Groton in May | ||||
| June | 60.6°F | 53.8°F | 69.1°F | cold |
| Ocean water temperature in Groton in June | ||||
| July | 68°F | 61.5°F | 74.5°F | warm |
| Ocean water temperature in Groton in July | ||||
| August | 70.2°F | 63.1°F | 75.4°F | warm |
| Ocean water temperature in Groton in August | ||||
| September | 68.4°F | 63.5°F | 73.8°F | warm |
| Ocean water temperature in Groton in September | ||||
| October | 63.3°F | 56.5°F | 68.7°F | cold |
| Ocean water temperature in Groton in October | ||||
| November | 55.8°F | 49.1°F | 62.6°F | cold |
| Ocean water temperature in Groton in November | ||||
| December | 47.8°F | 41°F | 53.6°F | cold |
| Ocean water temperature in Groton in December | ||||
Chart monthly average water temperature in Groton
