This data the coastal Sullivan 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.
Water temperature in Sullivan today is 60.8°F. Based on our historical data over a period of ten years, the warmest water in this day in Sullivan was recorded in 2018 and was 61.2°F, and the coldest was recorded in 2007 at 53.8°F. Sea water temperature in Sullivan is expected to drop to 57.2°F in the next 10 days. September average water temperature in Sullivan is 56.8°F, the minimum temperature is 53.1°F, and the maximum is 65.1°F.
Throughout the year, the water temperature in Sullivan does not rise above 68°F and therefore is not suitable for comfortable swimming. The average water temperature in Sullivan in winter reaches 41°F, in spring 41°F, in summer the average temperature rises to 55.8°F, and in autumn it is 53.6°F.
September 5, 2025 |
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today temp |
60.8°F |
September 4, 2025 |
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yesterday temp |
60.6°F |
The ocean salinity in Sullivan is 29.80‰, and the average salinity of the World Ocean is 35‰.
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 Sullivan. 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 Sullivan. Data in table shown for September 5, 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 |
---|---|---|---|
0' 10" | 0' 11" | 0' 11" | 0' 11" |
0.25 m | 0.27 m | 0.28 m | 0.27 m |
12-15 h | 15-18 h | 18-21 h | 21-24 h |
---|---|---|---|
1' 2" | 1' 3" | 1' 3" | 1' 7" |
0.35 m | 0.37 m | 0.38 m | 0.47 m |
Data in a table show Sullivan temperature today (September 5, 2025). For more information and forecast for a few days, go to the weather forecast Sullivan.
0-3 h | 3-6 h | 6-9 h | 9-12 h |
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![]() | ![]() | ![]() | ![]() |
58.1°F | 58.3°F | 58.1°F | 58.8°F |
12-15 h | 15-18 h | 18-21 h | 21-24 h |
---|---|---|---|
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60.4°F | 60.6°F | 60.8°F | 61°F |
You may also be interested in other sections of our site for Sullivan: Sunrise and Sunset, Tides
These figures shows the average, minimum and maximum monthly sea temperature in Sullivan. 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 Sullivan 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 | 40.5°F | 34°F | 45.5°F | cold |
Ocean water temperature in Sullivan in January | ||||
February | 37.2°F | 31.5°F | 41.4°F | cold |
Ocean water temperature in Sullivan in February | ||||
March | 36.9°F | 32.2°F | 42.4°F | cold |
Ocean water temperature in Sullivan in March | ||||
April | 40.1°F | 35.1°F | 44.8°F | cold |
Ocean water temperature in Sullivan in April | ||||
May | 45.9°F | 39.2°F | 54.5°F | cold |
Ocean water temperature in Sullivan in May | ||||
June | 51.8°F | 45°F | 61.9°F | cold |
Ocean water temperature in Sullivan in June | ||||
July | 57.2°F | 50.5°F | 66.2°F | cold |
Ocean water temperature in Sullivan in July | ||||
August | 58.5°F | 53.1°F | 68.5°F | cold |
Ocean water temperature in Sullivan in August | ||||
September | 56.8°F | 53.1°F | 65.1°F | cold |
Ocean water temperature in Sullivan in September | ||||
October | 54°F | 49.1°F | 58.8°F | cold |
Ocean water temperature in Sullivan in October | ||||
November | 50°F | 45.5°F | 55.6°F | cold |
Ocean water temperature in Sullivan in November | ||||
December | 45.1°F | 39.4°F | 50.2°F | cold |
Ocean water temperature in Sullivan in December |