Plum Island (NY) water temp
This data the coastal Plum 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 Plum Island
Water temperature in Plum Island today is 69.1°F. Based on our historical data over a period of ten years, the warmest water in this day in the Atlantic Ocean near Plum Island was recorded in 2021 and was 70.7°F, and the coldest was recorded in 2013 at 64.9°F. Sea water temperature in Plum Island is expected to drop to 65.8°F in the next 10 days. September average water temperature in Plum Island is 68.9°F, the minimum temperature is 64.8°F, and the maximum is 74.8°F.
The swimming season in Plum Island lasts from July to September. During those months, Plum Island water temperature does not drop below 68°F and therefore suitable for comfortable swimming. The average water temperature in Plum Island in winter reaches 42.8°F, in spring 45.5°F, in summer the average temperature rises to 67.1°F, and in autumn it is 62.8°F.
Plum Island water temperature now
| September 25, 2025 |
|---|
| today temp |
| 69.1°F |
| September 24, 2025 |
|---|
| yesterday temp |
| 69.3°F |
The ocean salinity in Plum Island is 27.44‰, and the average salinity of the World Ocean is 35‰.
Surf Forecast in Plum 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 Plum 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 Plum Island. Data in table shown for September 26, 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' 6" | 1' 5" | 1' 5" | 1' 9" |
| 0.46 m | 0.44 m | 0.43 m | 0.53 m |
| 12-15 h | 15-18 h | 18-21 h | 21-24 h |
|---|---|---|---|
| 1' 11" | 1' 11" | 1' 11" | 2' 4" |
| 0.58 m | 0.59 m | 0.59 m | 0.72 m |
Surf report in Plum Island
Plum Island weather forecast
Current temperature and weather
Data in a table show Plum Island temperature today (September 26, 2025). For more information and forecast for a few days, go to the weather forecast Plum Island.
| 0-3 h | 3-6 h | 6-9 h | 9-12 h |
|---|---|---|---|
 | | |  |
| 66.9°F | 66.7°F | 67.6°F | 69.1°F |
| 12-15 h | 15-18 h | 18-21 h | 21-24 h |
|---|---|---|---|
| | | |
| 70.3°F | 70°F | 70.2°F | 69.8°F |
You may also be interested in other sections of our site for Plum Island: Sunrise and Sunset, Tides
Plum Island water temperature by month
These figures shows the average, minimum and maximum monthly sea temperature in Plum 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 Plum 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 | 41.7°F | 36.7°F | 48.7°F | cold |
| Ocean water temperature in Plum Island in January | ||||
| February | 38.7°F | 32.4°F | 43.9°F | cold |
| Ocean water temperature in Plum Island in February | ||||
| March | 39.7°F | 32.7°F | 50.4°F | cold |
| Ocean water temperature in Plum Island in March | ||||
| April | 44.6°F | 36.3°F | 52.2°F | cold |
| Ocean water temperature in Plum Island in April | ||||
| May | 52°F | 45.1°F | 63°F | cold |
| Ocean water temperature in Plum Island in May | ||||
| June | 61.2°F | 54.5°F | 69.8°F | cold |
| Ocean water temperature in Plum Island in June | ||||
| July | 69.1°F | 62.6°F | 75°F | warm |
| Ocean water temperature in Plum Island in July | ||||
| August | 71.2°F | 65.8°F | 75.6°F | warm |
| Ocean water temperature in Plum Island in August | ||||
| September | 68.9°F | 64.8°F | 74.8°F | warm |
| Ocean water temperature in Plum Island in September | ||||
| October | 63.5°F | 56.5°F | 68.9°F | cold |
| Ocean water temperature in Plum Island in October | ||||
| November | 55.8°F | 49.1°F | 62.6°F | cold |
| Ocean water temperature in Plum Island in November | ||||
| December | 47.8°F | 41.4°F | 54°F | cold |
| Ocean water temperature in Plum Island in December | ||||
Chart monthly average water temperature in Plum Island
