Castine water temp
This data the coastal Castine 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 Castine
Water temperature in Castine today is 63°F. Based on our historical data over a period of ten years, the warmest water in this day in Castine was recorded in 2018 and was 63.3°F, and the coldest was recorded in 2007 at 56.3°F. Sea water temperature in Castine is expected to drop to 59.4°F in the next 10 days. September average water temperature in Castine is 59°F, the minimum temperature is 54.9°F, and the maximum is 64.9°F.
Throughout the year, the water temperature in Castine does not rise above 68°F and therefore is not suitable for comfortable swimming. But on some days of July, the water temperature warms up to 68°F and above. The average water temperature in Castine in winter reaches 39.9°F, in spring 41.4°F, in summer the average temperature rises to 58.6°F, and in autumn it is 54.7°F.
Castine water temperature now
| September 5, 2025 |
|---|
| today temp |
| 63°F |
| September 4, 2025 |
|---|
| yesterday temp |
| 61.7°F |
The ocean salinity in Castine is 29.54‰, and the average salinity of the World Ocean is 35‰.
Surf Forecast in Castine 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 Castine. 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 Castine. 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' 7" | 0' 8" | 0' 9" | 0' 11" |
| 0.18 m | 0.21 m | 0.22 m | 0.28 m |
| 12-15 h | 15-18 h | 18-21 h | 21-24 h |
|---|---|---|---|
| 1' 2" | 1' 3" | 1' 1" | 1' 3" |
| 0.36 m | 0.39 m | 0.33 m | 0.39 m |
Surf report in Castine
Castine weather forecast
Current temperature and weather
Data in a table show Castine temperature today (September 5, 2025). For more information and forecast for a few days, go to the weather forecast Castine.
| 0-3 h | 3-6 h | 6-9 h | 9-12 h |
|---|---|---|---|
 | | | |
| 59.4°F | 59.4°F | 59°F | 60.6°F |
| 12-15 h | 15-18 h | 18-21 h | 21-24 h |
|---|---|---|---|
|  |  | |
| 63.7°F | 68°F | 65.5°F | 64°F |
You may also be interested in other sections of our site for Castine: Sunrise and Sunset, Tides
Castine water temperature by month
These figures shows the average, minimum and maximum monthly sea temperature in Castine. 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 Castine 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 | 39.2°F | 34.7°F | 44.2°F | cold |
| Ocean water temperature in Castine in January | ||||
| February | 36.3°F | 32.2°F | 40.1°F | cold |
| Ocean water temperature in Castine in February | ||||
| March | 36.3°F | 32.4°F | 41.4°F | cold |
| Ocean water temperature in Castine in March | ||||
| April | 40.3°F | 34°F | 46.2°F | cold |
| Ocean water temperature in Castine in April | ||||
| May | 47.5°F | 40.3°F | 56.8°F | cold |
| Ocean water temperature in Castine in May | ||||
| June | 54.3°F | 48.4°F | 61.2°F | cold |
| Ocean water temperature in Castine in June | ||||
| July | 60.1°F | 53.1°F | 70.9°F | cold |
| Ocean water temperature in Castine in July | ||||
| August | 61.7°F | 55.9°F | 70°F | cold |
| Ocean water temperature in Castine in August | ||||
| September | 59°F | 54.9°F | 64.9°F | cold |
| Ocean water temperature in Castine in September | ||||
| October | 54.9°F | 49.8°F | 59.9°F | cold |
| Ocean water temperature in Castine in October | ||||
| November | 50°F | 44.8°F | 55.9°F | cold |
| Ocean water temperature in Castine in November | ||||
| December | 44.1°F | 38.7°F | 48.7°F | cold |
| Ocean water temperature in Castine in December | ||||
Chart monthly average water temperature in Castine
