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

Atmospheric River Bringing Heavy Rain to Southern California and Heavy Snow to the Sierra Nevadas

A strong atmospheric river will continue heavy rain over southern California through Friday. The heaviest rainfall is ongoing today in the Los Angeles Basin. Flash and urban flooding is possible. A prolonged heavy snowfall has begun over the Sierra Nevada Mountains and will continue through Friday. Travel will become increasingly difficult over the passes due to snow and strong winds. Read More >

Hazardous Weather Conditions

Current conditions at

LOS ALTOS (LOAC1)

Lat: 37.35472°NLon: 122.14167°WElev: 539.0ft.

NA

57°F

14°C

Humidity 78%
Wind Speed SSW 5 MPH
Barometer NA
Dewpoint 50°F (10°C)
Visibility NA
Last update 24 Dec 09:10 PM PST
Extended Forecast for

Los Altos CA

Flood Watch December 24, 09:50pm until December 26, 10:00pm
Wind Advisory until December 25, 10:00am
Click here for hazard details and duration
Flood Watch
Wind Advisory
  •  
    Flood Watch December 24, 09:50pm until December 26, 10:00pm
    Wind Advisory until December 25, 10:00am

    NOW: Multiple hazards in effect

    Click HERE for Details

  • Tonight

    Low: 54 °F

    Showers and
    Breezy

  • Christmas Day

    Christmas Day: Showers and possibly a thunderstorm before 1pm, then showers between 1pm and 4pm, then showers and possibly a thunderstorm after 4pm. Some of the storms could be severe. High near 58. South wind 16 to 20 mph, with gusts as high as 41 mph. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.

    High: 58 °F

    Severe
    Thunderstorms

  • Thursday Night

    Thursday Night: Showers and possibly a thunderstorm. Some of the storms could be severe. Low around 48. South southwest wind 16 to 21 mph, with gusts as high as 41 mph. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.

    Low: 48 °F

    Severe
    Thunderstorms
    then Showers

  • Friday

    Friday: Showers. High near 57. South wind around 10 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.

    High: 57 °F

    Showers

  • Friday Night

    Friday Night: Showers likely before 10pm, then a chance of showers and thunderstorms between 10pm and 1am, then a chance of showers after 1am. Mostly cloudy, with a low around 43. South wind around 5 mph. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    Low: 43 °F

    Showers
    Likely then
    Chance
    Showers

  • Saturday

    Saturday: A 20 percent chance of showers. Mostly sunny, with a high near 56.

    High: 56 °F

    Slight Chance
    Showers

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 38.

    Low: 38 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 56.

    High: 56 °F

    Sunny

Detailed Forecast

Tonight
Showers and possibly a thunderstorm. Steady temperature around 54. Breezy, with a south wind 22 to 29 mph, with gusts as high as 60 mph. Chance of precipitation is 90%. New rainfall amounts between a half and three quarters of an inch possible.
Christmas Day
Showers and possibly a thunderstorm before 1pm, then showers between 1pm and 4pm, then showers and possibly a thunderstorm after 4pm. Some of the storms could be severe. High near 58. South wind 16 to 20 mph, with gusts as high as 41 mph. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.
Thursday Night
Showers and possibly a thunderstorm. Some of the storms could be severe. Low around 48. South southwest wind 16 to 21 mph, with gusts as high as 41 mph. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.
Friday
Showers. High near 57. South wind around 10 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.
Friday Night
Showers likely before 10pm, then a chance of showers and thunderstorms between 10pm and 1am, then a chance of showers after 1am. Mostly cloudy, with a low around 43. South wind around 5 mph. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Saturday
A 20 percent chance of showers. Mostly sunny, with a high near 56.
Saturday Night
Mostly clear, with a low around 38.
Sunday
Sunny, with a high near 56.
Sunday Night
Patchy frost after 4am. Otherwise, clear, with a low around 37.
Monday
Patchy frost before 7am. Otherwise, sunny, with a high near 58.
Monday Night
Mostly clear, with a low around 39.
Tuesday
Sunny, with a high near 61.
Tuesday Night
Mostly clear, with a low around 42.
Wednesday
A slight chance of showers. Mostly sunny, with a high near 61.
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ABOUT THIS FORECAST

 
Point Forecast:
Los Altos CA
 37.37°N 122.1°W (Elev. 226 ft)
Last Update:
4:56 pm PST Dec 24, 2025
Forecast Valid:
9pm PST Dec 24, 2025-6pm PST Dec 31, 2025
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

Hourly Weather Forecast

National Digital Forecast Database

National Digital Forecast Database Maximum Temperature Forecast

High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation