Critical Fire Weather in the Southern High Plains; Heavy Snow in the Great Lakes and Northeast U.S.

Gusty winds and low relative humidity will bring elevated to critical fire weather conditions to the southern High Plains through the weekend. A winter storm will track across the Great Lakes and Northeast U.S. into Saturday with areas of wintry mix and heavy snow from northern New York through southern Maine. Read More >

Current conditions at

SJSU - Mount Diablo Summit Museum Rooftop (SJS02)

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

NA

28°F

-2°C

Humidity 99%
Wind Speed N 0 MPH
Barometer NA
Dewpoint 28°F (-2°C)
Visibility NA
Last update 20 Feb 03:25 AM PST
Extended Forecast for

Clayton CA

Cold Weather Advisory February 21, 01:00am until February 21, 09:00am
Click here for hazard details and duration
Cold Weather Advisory
  • Tonight

    Tonight: Increasing clouds, with a low around 38. South southeast wind 5 to 7 mph.

    Low: 38 °F

    Increasing
    Clouds

  • Saturday

    Saturday: Mostly cloudy, then gradually becoming sunny, with a high near 56. South wind 9 to 14 mph, with gusts as high as 25 mph.

    High: 56 °F

    Decreasing
    Clouds

  • Saturday Night

    Saturday Night: A 10 percent chance of rain after 4am.  Partly cloudy, with a low around 44. South southeast wind around 15 mph, with gusts as high as 25 mph.

    Low: 44 °F

    Partly Cloudy
    then Slight
    Chance Rain

  • Sunday

    Sunday: A 20 percent chance of rain before 10am.  Partly sunny, with a high near 62. Southeast wind 11 to 14 mph, with gusts as high as 21 mph.

    High: 62 °F

    Slight Chance
    Rain then
    Partly Sunny

  • Sunday Night

    Sunday Night: Mostly cloudy, with a low around 46. Southwest wind around 6 mph becoming east southeast after midnight.

    Low: 46 °F

    Mostly Cloudy

  • Monday

    Monday: A 30 percent chance of rain after 4pm.  Partly sunny, with a high near 63.

    High: 63 °F

    Partly Sunny
    then Chance
    Rain

  • Monday Night

    Monday Night: Rain, mainly after 10pm.  Low around 54. Chance of precipitation is 80%.

    Low: 54 °F

    Rain

  • Tuesday

    Tuesday: Rain.  Cloudy, with a high near 58.

    High: 58 °F

    Rain

  • Tuesday Night

    Tuesday Night: Rain, mainly before 10pm.  Cloudy, with a low around 53.

    Low: 53 °F

    Rain

Detailed Forecast

Tonight
Increasing clouds, with a low around 38. South southeast wind 5 to 7 mph.
Saturday
Mostly cloudy, then gradually becoming sunny, with a high near 56. South wind 9 to 14 mph, with gusts as high as 25 mph.
Saturday Night
A 10 percent chance of rain after 4am. Partly cloudy, with a low around 44. South southeast wind around 15 mph, with gusts as high as 25 mph.
Sunday
A 20 percent chance of rain before 10am. Partly sunny, with a high near 62. Southeast wind 11 to 14 mph, with gusts as high as 21 mph.
Sunday Night
Mostly cloudy, with a low around 46. Southwest wind around 6 mph becoming east southeast after midnight.
Monday
A 30 percent chance of rain after 4pm. Partly sunny, with a high near 63.
Monday Night
Rain, mainly after 10pm. Low around 54. Chance of precipitation is 80%.
Tuesday
Rain. Cloudy, with a high near 58.
Tuesday Night
Rain, mainly before 10pm. Cloudy, with a low around 53.
Wednesday
A chance of rain. Mostly cloudy, with a high near 60.
Wednesday Night
A chance of rain. Mostly cloudy, with a low around 51.
Thursday
A chance of rain. Partly sunny, with a high near 64.
Thursday Night
A chance of rain. Partly cloudy, with a low around 51.
Friday
A slight chance of rain. Mostly sunny, with a high near 65.
Basemap Options
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ABOUT THIS FORECAST

 
Point Forecast:
Clayton CA
 37.91°N 121.96°W (Elev. 1299 ft)
2:25 pm PST Feb 20, 2026
8pm PST Feb 20, 2026-6pm PST Feb 27, 2026
 
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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