Sister Bay water temp
This data the coastal Sister Bay 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 water temperature in Sister Bay
Water temperature in Sister Bay today is 59.9°F. Based on our historical data over a period of ten years, the warmest water in this day in Sister Bay was recorded in 2022 and was 67.8°F, and the coldest was recorded in 2014 at 59.2°F. Water temperature in Sister Bay is expected to rise to 62.8°F in the next 10 days. September average water temperature in Sister Bay is 64.2°F, the minimum temperature is 54.3°F, and the maximum is 71.2°F.
The swimming season in Sister Bay lasts from July to August. During those months, Sister Bay water temperature does not drop below 68°F and therefore suitable for comfortable swimming. The average water temperature in Sister Bay in winter reaches 36.5°F, in spring 38.1°F, in summer the average temperature rises to 63.5°F, and in autumn it is 55.8°F.
Sister Bay water temperature now
| September 13, 2025 |
|---|
| today temp |
| 59.9°F |
| September 12, 2025 |
|---|
| yesterday temp |
| 62.8°F |
Surf Forecast in Sister Bay 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 Sister Bay. 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 Sister Bay. Data in table shown for September 13, 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' 9" | 0' 7" | 0' 5" | 0' 5" |
| 0.23 m | 0.18 m | 0.12 m | 0.13 m |
| 12-15 h | 15-18 h | 18-21 h | 21-24 h |
|---|---|---|---|
| 0' 9" | 0' 6" | 0' 4" | 0' 7" |
| 0.22 m | 0.15 m | 0.11 m | 0.19 m |
Surf report in Sister Bay
Sister Bay weather forecast
Current temperature and weather
Data in a table show Sister Bay temperature today (September 13, 2025). For more information and forecast for a few days, go to the weather forecast Sister Bay.
| 0-3 h | 3-6 h | 6-9 h | 9-12 h |
|---|---|---|---|
 | | |  |
| 59.9°F | 60.1°F | 60.3°F | 61.9°F |
| 12-15 h | 15-18 h | 18-21 h | 21-24 h |
|---|---|---|---|
 |  | | |
| 63.9°F | 68.5°F | 64.8°F | 61.3°F |
You may also be interested in other sections of our site for Sister Bay: Sunrise and Sunset, Tides
Sister Bay water temperature by month
These figures shows the average, minimum and maximum monthly water temperature in Sister Bay. 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 Sister Bay 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 | 35.8°F | 31.1°F | 41.2°F | cold |
| Water temperature in Sister Bay in January | ||||
| February | 33.8°F | 29.8°F | 36.9°F | cold |
| Water temperature in Sister Bay in February | ||||
| March | 34.3°F | 31.1°F | 38.5°F | cold |
| Water temperature in Sister Bay in March | ||||
| April | 37°F | 32.5°F | 43.9°F | cold |
| Water temperature in Sister Bay in April | ||||
| May | 43°F | 35.4°F | 54.7°F | cold |
| Water temperature in Sister Bay in May | ||||
| June | 54.7°F | 42.1°F | 66.2°F | cold |
| Water temperature in Sister Bay in June | ||||
| July | 66.7°F | 53.8°F | 76.5°F | cold |
| Water temperature in Sister Bay in July | ||||
| August | 69.1°F | 61.9°F | 74.5°F | warm |
| Water temperature in Sister Bay in August | ||||
| September | 64.2°F | 54.3°F | 71.2°F | cold |
| Water temperature in Sister Bay in September | ||||
| October | 56.1°F | 47.5°F | 66.6°F | cold |
| Water temperature in Sister Bay in October | ||||
| November | 46.8°F | 38.7°F | 56.8°F | cold |
| Water temperature in Sister Bay in November | ||||
| December | 39.9°F | 32.9°F | 49.1°F | cold |
| Water temperature in Sister Bay in December | ||||
Chart monthly average water temperature in Sister Bay
