Half Moon Bay weather in August
August in Half Moon Bay: nice, dry, with clean air — one of the best months to visit.
Updated September 2026 · climate normals from ERA5 reanalysis
#2 of 12 months in Half Moon Bay · #463 of 1413 destinations to visit in August · comfort 85/100 (tier A)
- Days
- 20°C
- Nights
- 13°C
- Wet days
- 0
- Sun
- 11.7 h
- Humidity
- 86%
- Daylight
- 14 h
Traveller notes on Half Moon Bay in August
Notes from nearby San Francisco (35 km away)
Half Moon Bay doesn't have its own notes for August yet — these are about San Francisco, close enough to share the season.
I recently learned that "The coldest winter I experienced was a [summer/August... sources differ] spent in San Francisco" is apocryphal Mark Twain, but having just experienced San Francisco in August, I'm going to pretend I don't have that info. Brr! That fog does not play.
Add your own note from Half Moon Bay's card on the map.
Half Moon Bay climate normals — August
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Half Moon Bay in August
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
BusySummer break in United States, school holidays in 2 of the markets that fill it(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Half Moon Bay's weather
Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).
Best weatherHalf Moon Bay's weather peaks July–September.
Best weatherFair weatherToughest weather
Nearby, and something's on
Within 300 km of Half Moon Bay — a day trip or a short hop — with something on this month. Never part of the comfort score.
- Big Sur144 kmBlue and humpback whales offshore1 Jul – 15 Oct · usuallyWhale seasonmontereybaywhalewatch.com
- Yosemite National Park256 kmTioga and Glacier Point roads open10 May – 10 Nov · usuallyTrail seasonnps.gov
- Santa Cruz, California65 kmBoardwalk summer season23 May – 7 Sep · usuallySummer season opensbeachboardwalk.com
Where is Half Moon Bay?
Half Moon Bay in August — FAQ
- Is August a good time to visit Half Moon Bay?
- August in Half Moon Bay: nice, dry, with clean air — one of the best months to visit. It ranks #2 of 12 months for Half Moon Bay on SeasonMap's comfort score (85/100).
- What is the weather like in Half Moon Bay in August?
- In August, Half Moon Bay averages a daily high of 20.4°C and a low of 12.8°C, with about 2.2 mm of rain over roughly 0.4 rainy days.
- What is the air quality in Half Moon Bay in August?
- Half Moon Bay has a mean US Air Quality Index of about 44 in August.
Within 300 km: Big Sur's Blue and humpback whales offshore around 1 Jul – 15 Oct, and Yosemite National Park's Tioga and Glacier Point roads open around 10 May – 10 Nov.