National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Heavy Rainfall to Bring Flooding Threat to California; Heavy Snow in the Sierra

A strong atmospheric river will bring heavy rainfall to California through the holiday week. The heaviest rainfall is expected on Wednesday in the Los Angeles Basin. Flash and urban flooding is possible. A prolonged heavy snowfall is expected in the Sierra Nevada from the atmospheric river, raising concerns for major snow‐load impacts. Travel may be difficult to impossible over the passes. Read More >

Hazardous Weather Conditions

Current conditions at

Half Moon Bay Airport (KHAF)

Lat: 37.5136°NLon: 122.4996°WElev: 65.0ft.

Mist

59°F

15°C

Humidity 100%
Wind Speed S 36 MPH
Barometer 29.56 in (1001.02 mb)
Dewpoint 59°F (15°C)
Visibility 5.00 mi
Last update 23 Dec 08:55 PM PST
Extended Forecast for

Half Moon Bay CA

Flood Watch December 23, 09:02pm until December 26, 10:00pm
High Wind Warning until December 24, 04:00am
Click here for hazard details and duration
Flood Watch
High Wind Warning
  •  
    Flood Watch December 23, 09:02pm until December 26, 10:00pm
    High Wind Warning until December 24, 04:00am

    NOW: Multiple hazards in effect

    Click HERE for Details

  • Tonight

    Low: 51 °F

    Showers and
    Windy

  • Wednesday

    Wednesday: Showers. High near 61. Breezy, with a south wind 13 to 23 mph, with gusts as high as 26 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.

    High: 61 °F

    Showers and
    Breezy

  • Wednesday Night

    Wednesday Night: Showers and possibly a thunderstorm. Some of the storms could be severe. Low around 49. Breezy, with a south wind 25 to 29 mph, with gusts as high as 55 mph. Chance of precipitation is 100%. New rainfall amounts between a half and three quarters of an inch possible.

    Low: 49 °F

    Severe
    Thunderstorms
    and Breezy

  • Christmas Day

    Christmas Day: Showers and possibly a thunderstorm before 7am, then showers between 7am and 1pm, then showers and possibly a thunderstorm after 1pm. High near 58. Breezy, with a south southwest wind around 26 mph, with gusts as high as 47 mph. Chance of precipitation is 100%. New rainfall amounts between a half and three quarters of an inch possible.

    High: 58 °F

    Showers and
    Breezy

  • Thursday Night

    Thursday Night: Showers and possibly a thunderstorm. Low around 47. Breezy, with a south southwest wind 18 to 22 mph, with gusts as high as 39 mph. Chance of precipitation is 100%. New precipitation amounts between a half and three quarters of an inch possible.

    Low: 47 °F

    Showers and
    Breezy

  • Friday

    Friday: Showers. High near 58. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.

    High: 58 °F

    Showers

  • Friday Night

    Friday Night: Showers and possibly a thunderstorm. Low around 44. Chance of precipitation is 80%.

    Low: 44 °F

    Showers

  • Saturday

    Saturday: A chance of showers. Mostly sunny, with a high near 57.

    High: 57 °F

    Chance
    Showers

Detailed Forecast

Tonight
Showers, with thunderstorms also possible after 1am. Low around 51. Windy, with a south southeast wind 25 to 30 mph increasing to 35 to 40 mph after midnight. Winds could gust as high as 60 mph. Chance of precipitation is 100%. New rainfall amounts between a quarter and half of an inch possible.
Wednesday
Showers. High near 61. Breezy, with a south wind 13 to 23 mph, with gusts as high as 26 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.
Wednesday Night
Showers and possibly a thunderstorm. Some of the storms could be severe. Low around 49. Breezy, with a south wind 25 to 29 mph, with gusts as high as 55 mph. Chance of precipitation is 100%. New rainfall amounts between a half and three quarters of an inch possible.
Christmas Day
Showers and possibly a thunderstorm before 7am, then showers between 7am and 1pm, then showers and possibly a thunderstorm after 1pm. High near 58. Breezy, with a south southwest wind around 26 mph, with gusts as high as 47 mph. Chance of precipitation is 100%. New rainfall amounts between a half and three quarters of an inch possible.
Thursday Night
Showers and possibly a thunderstorm. Low around 47. Breezy, with a south southwest wind 18 to 22 mph, with gusts as high as 39 mph. Chance of precipitation is 100%. New precipitation amounts between a half and three quarters of an inch possible.
Friday
Showers. High near 58. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.
Friday Night
Showers and possibly a thunderstorm. Low around 44. Chance of precipitation is 80%.
Saturday
A chance of showers. Mostly sunny, with a high near 57.
Saturday Night
Mostly clear, with a low around 41.
Sunday
Sunny, with a high near 57.
Sunday Night
Mostly clear, with a low around 40.
Monday
Sunny, with a high near 58.
Monday Night
Mostly clear, with a low around 42.
Tuesday
Sunny, with a high near 60.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Half Moon Bay CA
 37.48°N 122.42°W (Elev. 397 ft)
Last Update:
8:18 pm PST Dec 23, 2025
Forecast Valid:
9pm PST Dec 23, 2025-6pm PST Dec 30, 2025
 
Forecast Discussion
 
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Additional Resources

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High Temperature

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Chance of Precipitation