Half Moon Bay (CA) Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit Half Moon Bay.
Climate overview of Half Moon Bay
Temperatures in Half Moon Bay, California, United States of America, shift moderately through the seasons. The warmest month is September at 22°C (72°F), and the coolest is December at 15°C (59°F).
With around 625 mm (25 in) of annual rainfall, the city has moderate precipitation levels. December is the wettest month and July the driest. It also has a distinct dry season from May to October. The sunniest month is May, with 10.8 hours of sunshine per day on average.
Half Moon Bay Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in Half Moon Bay — and find the best time to visit.
Monthly Temperature in Half Moon Bay
In Half Moon Bay, seasonal changes bring about a moderate variation in temperatures. Typically, average maximum daytime temperatures range from a comfortable 22°C (72°F) in September to a moderate 15°C (59°F) in the coolest month, December.
Nights vary from 12°C (54°F) in September to around 6°C (43°F) during the colder months.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in Half Moon Bay
Generally, Half Moon Bay receives mid-range precipitation levels, with 625 mm (25 in) annually. The climate in Half Moon Bay shows significant variation throughout the year. Expect high rainfall in December, the wettest month, with an average of 144 mm (5.7 in) of precipitation over 14 rainy days.
In contrast, the driest month July offers drier and sunnier days, with around 3 mm (0.1 in) of rainfall over 5 rainy days. For more details, please visit our Half Moon Bay Precipitation page.
The mean monthly precipitation over the year, including rain, hail, and snow
The average number of days each month with precipitation
Sunshine Hours in Half Moon Bay
For those who appreciate different seasons, Half Moon Bay serves as an ideal destination. Expect longer, more sun-filled days in May with an average of 10.8 hours of sunshine daily, and embrace the darker days in December, offering only 5.3 hours of daily sunlight.
Visit our detailed sunshine hours page for more information.
Monthly hours of sunshine
Daily hours of sunshine
Daily percentage of sunshine
Water Temperature in Half Moon Bay
The mean water temperature over the year ranges from 12°C (54°F) in January to 14°C (57°F) in June.
Water temperature over the year
Humidity in Half Moon Bay by Month
The relative humidity is high throughout the year in Half Moon Bay.
The city experiences its highest humidity in January, reaching 80%. In June, the humidity drops to its lowest level at 71%. What does this mean? Read our detailed page on humidity levels for further details.
Relative humidity over the year
Wind Speed in Half Moon Bay
The average wind speed over the year ranges from 3 m/s (6 knots) to 7 m/s (14 knots). It is lower in January, November and December and higher in June and July. What does this mean?
The mean monthly wind speed over the year (meters per second)
Best Time to Visit Half Moon Bay
Frequently asked questions about the climate in Half Moon Bay
What is the best time to visit Half Moon Bay?
May, June, July, August, September and October typically offer the most optimal weather in Half Moon Bay. In contrast, February, March and December tend to have less optimal conditions. Half Moon Bay has a distinct dry season from May to October.
What temperatures can I expect in Half Moon Bay?
Daytime highs range from 15°C (59°F) in December to 22°C (72°F) in September. Nighttime lows range from 6°C (43°F) to 12°C (54°F).
How much rain does Half Moon Bay get?
Annual rainfall is around 625 mm (25 in). December is the wettest month with 144 mm (5.7 in), while July is the driest with 3 mm (0.1 in).
How sunny is Half Moon Bay?
Half Moon Bay receives around 3,058 hours of sunshine per year. May is the sunniest month with 324 hours, while December is the cloudiest with just 160 hours. Overall, Half Moon Bay enjoys abundant sunshine.
Half Moon Bay 3-Day Forecast
Half Moon Bay (CA) 3-Day Forecast
Half Moon Bay on the map
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