Half Moon Bay weather in March

March in Half Moon Bay: cool, rainy, with muggy air — a good time to visit.

Updated September 2026 · climate normals from ERA5 reanalysis

Half Moon Bay🇺🇸 United States · California · Beach65
  1. 57Jan
  2. 66Feb
  3. 65Mar
  4. 78Apr
  5. 77May
  6. 82Jun
  7. 84Jul
  8. 85Aug
  9. 87Sep
  10. 79Oct
  11. 70Nov
  12. 50Dec

#10 of 12 months in Half Moon Bay · #1108 of 1413 destinations to visit in March · comfort 65/100 (tier C)

Days
14°C
Nights
7°C
Wet days
12
Sun
9.2 h
Humidity
82%
Daylight
12 h
Half Moon Bay, United States
Photo: Doc Searls · CC BY-SA 2.0

Traveller notes on Half Moon Bay in March

Notes from nearby San Francisco (35 km away)

Half Moon Bay doesn't have its own notes for March yet — these are about San Francisco, close enough to share the season.

Forum posters describe March as one of the most changeable months in San Francisco - it could be warm, cold or rainy, with morning lows typically in the mid-to-upper 40sF and afternoon highs in the low-to-mid 60sF. Posters are consistent that any lingering rain is generally the tail end of the rainy season, with the major winter storms usually done by late March, though posters note it doesn't necessarily turn warm either - even in a typical year, only 2-3 days in the back half of the month might bring genuinely warm weather. Posters consistently emphasize real block-to-block variability, with temperatures feeling 5-10 degrees different between a sunny and shady side of the same street, and a 70F day cooling down to 50F by night. Posters generally recommend serious layers plus a lightweight raincoat regardless of the specific forecast.
Tripadvisor community · March · 6 days ago · about San Francisco · Read more on Tripadvisor ↗

Add your own note from Half Moon Bay's card on the map.

Half Moon Bay climate normals — March

Daytime high14°C / 57°F🙂 cool
Nighttime low7°C / 44°F
Sea temperature11°C / 52°F🥶 cold sea
Rainfall118 mm / 4.6 in🌧 rainy
Rainy days12 days
Humidity82%💦 very humid
Dew point6°C / 43°F
Sunshine9.2 h/day
Daylight12 h
Wind19 km/h / 12 mph
Air quality (US AQI)51🙂 moderate

Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.

Crowds in Half Moon Bay in March

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.

BusySpring break in United States(estimated)

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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).

Toughest weatherHalf Moon Bay's weather peaks July–September.

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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?

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Half Moon Bay in March — FAQ

Is March a good time to visit Half Moon Bay?
March in Half Moon Bay: cool, rainy, with muggy air — a good time to visit. It ranks #10 of 12 months for Half Moon Bay on SeasonMap's comfort score (65/100).
What is the weather like in Half Moon Bay in March?
In March, Half Moon Bay averages a daily high of 14°C and a low of 6.9°C, with about 117.7 mm of rain over roughly 12.4 rainy days.
What is the air quality in Half Moon Bay in March?
Half Moon Bay has a mean US Air Quality Index of about 51 in March.

Within 300 km: San Francisco's Plum and magnolia blossom around 25 Jan – 15 Mar, and Santa Cruz, California's Gray whale migration around 15 Dec – 15 Apr.