Half Moon Bay Beach Water Temperature
Sea-surface temperature at Half Moon Bay Beach, California · times in PDT
Updated 4:03 AM PDT
How it compares today
Water temperature through the year
Monthly normals computed from 2023–2025 daily sea-surface temperature history.
Nearby water right now
7-day outlook
| Day | Air high / low | Max UV | Rain |
|---|---|---|---|
| Fri, Aug 28 | 66° / 56° | 7 | 7% |
| Sat, Aug 29 | 65° / 56° | 7 | 4% |
| Sun, Aug 30 | 68° / 58° | 7 | 3% |
| Mon, Aug 31 | 69° / 58° | 7 | 5% |
| Tue, Sep 1 | 69° / 57° | 7 | 4% |
| Wed, Sep 2 | 70° / 56° | 6 | 2% |
| Thu, Sep 3 | 71° / 58° | 7 | 6% |
Sea-surface temperature and wave data from the Open-Meteo marine model; weather from Open-Meteo.
Is Half Moon Bay Beach warm enough to swim?
At 59°F, the water at Half Moon Bay Beach is chilly — wetsuit recommended. Most swimmers are comfortable without a wetsuit above 72°F; below 62°F, cold-water shock becomes a real risk for unprotected swimmers.
That is right on the August average of 59°F for this beach.
The water here never averages above 70°F — even in September, the warmest month, it sits around 61°F. Most people wear a wetsuit.
Frequently asked questions
How warm is the water at Half Moon Bay Beach right now?
The sea-surface temperature is about 59°F. That is right on the August average of 59°F for this beach.
When is the water warm enough to swim at Half Moon Bay Beach?
The water here never averages above 70°F — even in September, the warmest month, it sits around 61°F. Most people wear a wetsuit.
What is the warmest the water gets at Half Moon Bay Beach?
Around 61°F in September, based on 2023–2025 records. The coolest month is March at roughly 54°F.