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

Heavy Rain and Mountain Snow Lingers in California; Winter Storm Impacting the Great Lakes and Northeast U.S.

An atmospheric river will wind down through today across California with lingering heavy rainfall, heavy mountain snow, and gusty winds. A wintry mix of freezing rain, sleet, and snow will cause hazardous travel conditions for the Great Lakes into the northern Mid-Atlantic and southern New England today through Saturday morning. Areas of tree damage and power outages are possible. Read More >

Hazardous Weather Conditions

Current conditions at

SJSU - Mount Diablo Summit Museum Rooftop (SJS02)

Lat: 37.881699°NLon: 121.914173°WElev: 3904.0ft.

NA

38°F

3°C

Humidity 100%
Wind Speed SSW 16 MPH
Barometer NA
Dewpoint 38°F (3°C)
Visibility NA
Wind Chill29°F (-2°C)
Last update 26 Dec 06:20 AM PST
Extended Forecast for

4 Miles SSE Clayton CA

Flood Watch December 26, 06:44am until December 26, 10:00pm
Click here for hazard details and duration
Flood Watch
  •  
    Flood Watch December 26, 06:44am until December 26, 10:00pm

    NOW until 10:00pm Fri

    Flood Watch

  • Today

    High: 46 °F

    Chance
    Showers and
    Breezy

  • Tonight

    Tonight: Mostly cloudy, with a steady temperature around 44. West southwest wind around 9 mph, with gusts as high as 18 mph.

    Low: 44 °F

    Mostly Cloudy

  • Saturday

    Saturday: Mostly sunny, with a steady temperature around 42. West wind around 7 mph becoming north in the afternoon.

    High: 42 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 38. North northwest wind around 6 mph.

    Low: 38 °F

    Partly Cloudy

  • Sunday

    Sunday: Sunny, with a high near 46. North northeast wind around 8 mph.

    High: 46 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 37.

    Low: 37 °F

    Mostly Clear

  • Monday

    Monday: Sunny, with a high near 47.

    High: 47 °F

    Sunny

  • Monday Night

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

    Low: 38 °F

    Mostly Clear

Detailed Forecast

Today
A slight chance of showers before 9am, then a chance of showers after 10am. Partly sunny, with a high near 46. Breezy, with a south southwest wind 14 to 22 mph, with gusts as high as 40 mph. Chance of precipitation is 50%. New precipitation amounts between a tenth and quarter of an inch possible.
Tonight
Mostly cloudy, with a steady temperature around 44. West southwest wind around 9 mph, with gusts as high as 18 mph.
Saturday
Mostly sunny, with a steady temperature around 42. West wind around 7 mph becoming north in the afternoon.
Saturday Night
Partly cloudy, with a low around 38. North northwest wind around 6 mph.
Sunday
Sunny, with a high near 46. North northeast wind around 8 mph.
Sunday Night
Mostly clear, with a low around 37.
Monday
Sunny, with a high near 47.
Monday Night
Mostly clear, with a low around 38.
Tuesday
Sunny, with a high near 48.
Tuesday Night
Mostly clear, with a low around 40.
Wednesday
Mostly sunny, with a high near 48.
Wednesday Night
A slight chance of showers. Mostly cloudy, with a low around 43.
New Year's Day
A chance of showers. Mostly cloudy, with a high near 50.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
4 Miles SSE Clayton CA
 37.87°N 121.92°W (Elev. 2818 ft)
Last Update:
3:07 am PST Dec 26, 2025
Forecast Valid:
6am PST Dec 26, 2025-6pm PST Jan 1, 2026
 
Forecast Discussion
 
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Additional Resources

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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