Half Moon Bay water temp
This data the coastal Half Moon Bay 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 Half Moon Bay
Water temperature in Half Moon Bay today is 61.2°F. Based on our historical data over a period of ten years, the warmest water in this day in Half Moon Bay was recorded in 2014 and was 63.5°F, and the coldest was recorded in 2012 at 55.9°F. Sea water temperature in Half Moon Bay is expected to drop to 58.5°F in the next 10 days. September average water temperature in Half Moon Bay is 58.6°F, the minimum temperature is 52.7°F, and the maximum is 63.9°F.
Throughout the year, the water temperature in Half Moon Bay does not rise above 68°F and therefore is not suitable for comfortable swimming. The average water temperature in Half Moon Bay in winter reaches 54°F, in spring 53.1°F, in summer the average temperature rises to 56.1°F, and in autumn it is 57.2°F.
Half Moon Bay water temperature now
| September 20, 2025 |
|---|
| today temp |
| 61.2°F |
| September 19, 2025 |
|---|
| yesterday temp |
| 61.2°F |
The ocean salinity in Half Moon Bay is 32.97‰, and the average salinity of the World Ocean is 35‰.
Surf Forecast in Half Moon 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 Half Moon 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 Half Moon Bay. Data in table shown for September 20, 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 |
|---|---|---|---|
| 4' 8" | 4' 5" | 4' 3" | 4' 0" |
| 1.42 m | 1.35 m | 1.29 m | 1.23 m |
| 12-15 h | 15-18 h | 18-21 h | 21-24 h |
|---|---|---|---|
| 3' 11" | 3' 9" | 3' 8" | 3' 8" |
| 1.19 m | 1.15 m | 1.13 m | 1.11 m |
Surf report in Half Moon Bay
Half Moon Bay weather forecast
Current temperature and weather
Data in a table show Half Moon Bay temperature today (September 20, 2025). For more information and forecast for a few days, go to the weather forecast Half Moon Bay.
| 0-3 h | 3-6 h | 6-9 h | 9-12 h |
|---|---|---|---|
 | | |  |
| 59.7°F | 59.4°F | 59.2°F | 59.7°F |
| 12-15 h | 15-18 h | 18-21 h | 21-24 h |
|---|---|---|---|
 |  | | |
| 63.7°F | 64.8°F | 62.4°F | 60.4°F |
You may also be interested in other sections of our site for Half Moon Bay: Sunrise and Sunset, Tides
Half Moon Bay water temperature by month
These figures shows the average, minimum and maximum monthly sea temperature in Half Moon 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 Half Moon 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 | 53.8°F | 49.8°F | 57.9°F | cold |
| Ocean water temperature in Half Moon Bay in January | ||||
| February | 53.6°F | 49.8°F | 59.2°F | cold |
| Ocean water temperature in Half Moon Bay in February | ||||
| March | 53.4°F | 48.7°F | 58.1°F | cold |
| Ocean water temperature in Half Moon Bay in March | ||||
| April | 52.7°F | 48.6°F | 57.6°F | cold |
| Ocean water temperature in Half Moon Bay in April | ||||
| May | 53.1°F | 47.7°F | 57.9°F | cold |
| Ocean water temperature in Half Moon Bay in May | ||||
| June | 54.7°F | 49.1°F | 59.4°F | cold |
| Ocean water temperature in Half Moon Bay in June | ||||
| July | 56.1°F | 46.8°F | 62.6°F | cold |
| Ocean water temperature in Half Moon Bay in July | ||||
| August | 57.7°F | 49.5°F | 64°F | cold |
| Ocean water temperature in Half Moon Bay in August | ||||
| September | 58.6°F | 52.7°F | 63.9°F | cold |
| Ocean water temperature in Half Moon Bay in September | ||||
| October | 57.2°F | 53.1°F | 63.3°F | cold |
| Ocean water temperature in Half Moon Bay in October | ||||
| November | 55.8°F | 50.5°F | 61°F | cold |
| Ocean water temperature in Half Moon Bay in November | ||||
| December | 54.7°F | 51.3°F | 60.3°F | cold |
| Ocean water temperature in Half Moon Bay in December | ||||
Chart monthly average water temperature in Half Moon Bay
