Hewlett Harbor water temp
This data the coastal Hewlett Harbor sea 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 sea temperature in Hewlett Harbor
Water temperature in Hewlett Harbor today is 69.4°F. Based on our historical data over a period of ten years, the warmest water in this day in Hewlett Harbor was recorded in 2021 and was 72.1°F, and the coldest was recorded in 2013 at 65.8°F. Sea water temperature in Hewlett Harbor is expected to drop to 66.6°F in the next 10 days. September average water temperature in Hewlett Harbor is 70.9°F, the minimum temperature is 64.6°F, and the maximum is 77°F.
The swimming season in Hewlett Harbor lasts from July to September. During those months, Hewlett Harbor water temperature does not drop below 68°F and therefore suitable for comfortable swimming. The average water temperature in Hewlett Harbor in winter reaches 43.9°F, in spring 47.8°F, in summer the average temperature rises to 70.9°F, and in autumn it is 63.5°F.
Hewlett Harbor water temperature now
| September 26, 2025 |
|---|
| today temp |
| 69.4°F |
| September 25, 2025 |
|---|
| yesterday temp |
| 69.8°F |
The sea salinity in Hewlett Harbor is 29.58‰, and the average salinity of the World Ocean is 35‰.
Surf Forecast in Hewlett Harbor 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 Hewlett Harbor. 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 Hewlett Harbor. 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 |
|---|---|---|---|
| 3' 1" | 3' 1" | 2' 11" | 2' 7" |
| 0.94 m | 0.95 m | 0.9 m | 0.8 m |
| 12-15 h | 15-18 h | 18-21 h | 21-24 h |
|---|---|---|---|
| 2' 5" | 2' 4" | 2' 2" | 2' 2" |
| 0.73 m | 0.7 m | 0.67 m | 0.66 m |
Surf report in Hewlett Harbor
Hewlett Harbor weather forecast
Current temperature and weather
Data in a table show Hewlett Harbor temperature today (September 26, 2025). For more information and forecast for a few days, go to the weather forecast Hewlett Harbor.
| 0-3 h | 3-6 h | 6-9 h | 9-12 h |
|---|---|---|---|
 | | |  |
| 70.9°F | 68.2°F | 66.4°F | 70.7°F |
| 12-15 h | 15-18 h | 18-21 h | 21-24 h |
|---|---|---|---|
 | | | |
| 75.9°F | 82°F | 80.6°F | 75°F |
You may also be interested in other sections of our site for Hewlett Harbor: Sunrise and Sunset, Tides
Hewlett Harbor water temperature by month
These figures shows the average, minimum and maximum monthly sea temperature in Hewlett Harbor. 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 Hewlett Harbor 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 | 43.2°F | 37.2°F | 50°F | cold |
| Sea water temperature in Hewlett Harbor in January | ||||
| February | 39.9°F | 34.9°F | 45°F | cold |
| Sea water temperature in Hewlett Harbor in February | ||||
| March | 41.5°F | 36.1°F | 50.7°F | cold |
| Sea water temperature in Hewlett Harbor in March | ||||
| April | 46.6°F | 39.4°F | 53.8°F | cold |
| Sea water temperature in Hewlett Harbor in April | ||||
| May | 55.2°F | 47.7°F | 66.6°F | cold |
| Sea water temperature in Hewlett Harbor in May | ||||
| June | 65.3°F | 56.5°F | 74.5°F | cold |
| Sea water temperature in Hewlett Harbor in June | ||||
| July | 73.2°F | 65.7°F | 79.2°F | warm |
| Sea water temperature in Hewlett Harbor in July | ||||
| August | 74.1°F | 68.7°F | 78.4°F | warm |
| Sea water temperature in Hewlett Harbor in August | ||||
| September | 70.9°F | 64.6°F | 77°F | warm |
| Sea water temperature in Hewlett Harbor in September | ||||
| October | 63.7°F | 56.8°F | 71.1°F | cold |
| Sea water temperature in Hewlett Harbor in October | ||||
| November | 55.8°F | 49.3°F | 62.8°F | cold |
| Sea water temperature in Hewlett Harbor in November | ||||
| December | 48.6°F | 40.8°F | 55.9°F | cold |
| Sea water temperature in Hewlett Harbor in December | ||||
Chart monthly average water temperature in Hewlett Harbor
