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

San Jose / Reid / Hillv (KRHV)

Lat: 37.33333°NLon: 121.81667°WElev: 135.0ft.

Mostly Cloudy

57°F

14°C

Humidity 71%
Wind Speed SE 6 MPH
Barometer 29.85 in (1010.84 mb)
Dewpoint 48°F (9°C)
Visibility 10.00 mi
Last update 25 Dec 08:55 AM PST
Extended Forecast for

Mount Hamilton CA

Flood Watch December 25, 09:15am until December 26, 10:00pm
Wind Advisory December 25, 09:15am until December 25, 10:00am
Click here for hazard details and duration
Flood Watch
...
  •  
    Flood Watch December 25, 09:15am until December 26, 10:00pm
    Wind Advisory December 25, 09:15am until December 25, 10:00am

    NOW: Multiple hazards in effect

    Click HERE for Details

  • Christmas Day

    High: 48 °F

    Severe
    Thunderstorms
    and Breezy

  • Tonight

    Tonight: Rain and possibly a thunderstorm. Some of the storms could be severe. Steady temperature around 46. Southwest wind 18 to 21 mph, with gusts as high as 36 mph. Chance of precipitation is 100%. New precipitation amounts between a half and three quarters of an inch possible.

    Low: 46 °F

    Severe
    Thunderstorms
    then Rain

  • Friday

    Friday: Rain. High near 46. South wind 10 to 16 mph, with gusts as high as 26 mph. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.

    High: 46 °F

    Rain

  • Friday Night

    Friday Night: Rain likely, mainly before 10pm. Mostly cloudy, with a low around 39. Southwest wind around 6 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

    Low: 39 °F

    Rain Likely
    then Chance
    Rain

  • Saturday

    Saturday: A 20 percent chance of rain. Mostly sunny, with a high near 47. Northwest wind around 7 mph.

    High: 47 °F

    Slight Chance
    Rain

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 35.

    Low: 35 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 48.

    High: 48 °F

    Sunny

  • Sunday Night

    Sunday Night: Clear, with a low around 36.

    Low: 36 °F

    Clear

Detailed Forecast

Christmas Day
Rain before 10am, then showers and possibly a thunderstorm between 10am and 4pm, then rain after 4pm. Some of the storms could be severe. High near 48. Breezy, with a south wind 22 to 28 mph, with gusts as high as 45 mph. Chance of precipitation is 100%. New rainfall amounts between a quarter and half of an inch possible.
Tonight
Rain and possibly a thunderstorm. Some of the storms could be severe. Steady temperature around 46. Southwest wind 18 to 21 mph, with gusts as high as 36 mph. Chance of precipitation is 100%. New precipitation amounts between a half and three quarters of an inch possible.
Friday
Rain. High near 46. South wind 10 to 16 mph, with gusts as high as 26 mph. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.
Friday Night
Rain likely, mainly before 10pm. Mostly cloudy, with a low around 39. Southwest wind around 6 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.
Saturday
A 20 percent chance of rain. Mostly sunny, with a high near 47. Northwest wind around 7 mph.
Saturday Night
Mostly clear, with a low around 35.
Sunday
Sunny, with a high near 48.
Sunday Night
Clear, with a low around 36.
Monday
Sunny, with a high near 54.
Monday Night
Clear, with a low around 40.
Tuesday
Sunny, with a high near 58.
Tuesday Night
Mostly clear, with a low around 43.
Wednesday
Partly sunny, with a high near 59.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Mount Hamilton CA
 37.35°N 121.64°W (Elev. 2398 ft)
Last Update:
8:59 am PST Dec 25, 2025
Forecast Valid:
9am PST Dec 25, 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