Half Moon Bay weather in May
May in Half Moon Bay: nice, a little rain, with clean air — a great time to visit.
Updated September 2026 · climate normals from ERA5 reanalysis
#7 of 12 months in Half Moon Bay · #853 of 1413 destinations to visit in May · comfort 77/100 (tier B)
- Days
- 16°C
- Nights
- 9°C
- Wet days
- 5
- Sun
- 11.9 h
- Humidity
- 82%
- Daylight
- 14 h
Traveller notes on Half Moon Bay in May
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Half Moon Bay climate normals — May
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Half Moon Bay in May
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.
Shoulder seasonan ordinary month(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).
Fair 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.
Where is Half Moon Bay?
Half Moon Bay in May — FAQ
- Is May a good time to visit Half Moon Bay?
- May in Half Moon Bay: nice, a little rain, with clean air — a great time to visit. It ranks #7 of 12 months for Half Moon Bay on SeasonMap's comfort score (77/100).
- What is the weather like in Half Moon Bay in May?
- In May, Half Moon Bay averages a daily high of 16.4°C and a low of 9.2°C, with about 38.4 mm of rain over roughly 5.4 rainy days.
- What is the air quality in Half Moon Bay in May?
- Half Moon Bay has a mean US Air Quality Index of about 48 in May.
Within 300 km: San Francisco's Gray whale migration around 15 Dec – 15 May, and Monterey's Gray whale migration around 15 Dec – 10 May.