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

4 Miles SSE Clayton CA

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

    This Afternoon: Partly sunny, with a high near 42. South wind around 5 mph.

    High: 42 °F

    Partly Sunny

  • Tonight

    Tonight: Partly cloudy, with a low around 35. South southeast wind 6 to 10 mph, with gusts as high as 18 mph.

    Low: 35 °F

    Partly Cloudy

  • Saturday

    Saturday: Mostly sunny, with a high near 48. South wind 13 to 17 mph, with gusts as high as 31 mph.

    High: 48 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: A 10 percent chance of rain after 4am.  Partly cloudy, with a low around 41. South southeast wind around 18 mph, with gusts as high as 32 mph.

    Low: 41 °F

    Mostly Clear
    then Slight
    Chance Rain

  • Sunday

    Sunday: A 20 percent chance of rain before 10am.  Mostly sunny, with a high near 58. Southeast wind 15 to 18 mph, with gusts as high as 28 mph.

    High: 58 °F

    Slight Chance
    Rain then
    Partly Sunny

  • Sunday Night

    Sunday Night: Mostly cloudy, with a low around 46.

    Low: 46 °F

    Mostly Cloudy

  • Monday

    Monday: A 30 percent chance of rain after 4pm.  Partly sunny, with a high near 59.

    High: 59 °F

    Partly Sunny
    then Chance
    Rain

  • Monday Night

    Monday Night: Rain, mainly after 10pm.  Cloudy, with a low around 54.

    Low: 54 °F

    Rain

  • Tuesday

    Tuesday: Rain.  Cloudy, with a high near 57.

    High: 57 °F

    Rain

Detailed Forecast

This Afternoon
Partly sunny, with a high near 42. South wind around 5 mph.
Tonight
Partly cloudy, with a low around 35. South southeast wind 6 to 10 mph, with gusts as high as 18 mph.
Saturday
Mostly sunny, with a high near 48. South wind 13 to 17 mph, with gusts as high as 31 mph.
Saturday Night
A 10 percent chance of rain after 4am. Partly cloudy, with a low around 41. South southeast wind around 18 mph, with gusts as high as 32 mph.
Sunday
A 20 percent chance of rain before 10am. Mostly sunny, with a high near 58. Southeast wind 15 to 18 mph, with gusts as high as 28 mph.
Sunday Night
Mostly cloudy, with a low around 46.
Monday
A 30 percent chance of rain after 4pm. Partly sunny, with a high near 59.
Monday Night
Rain, mainly after 10pm. Cloudy, with a low around 54.
Tuesday
Rain. Cloudy, with a high near 57.
Tuesday Night
Rain, mainly before 10pm. Cloudy, with a low around 52.
Wednesday
A chance of rain. Mostly cloudy, with a high near 56.
Wednesday Night
A chance of rain. Mostly cloudy, with a low around 50.
Thursday
A chance of rain. Partly sunny, with a high near 60.
Basemap Options
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ABOUT THIS FORECAST

 
Point Forecast:
4 Miles SSE Clayton CA
 37.87°N 121.92°W (Elev. 2818 ft)
12:26 pm PST Feb 20, 2026
1pm PST Feb 20, 2026-6pm PST Feb 26, 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