Heat the Southwest; Fire Weather in the Central U.S.; Kona Low Impacting Hawaii

A rare March heat wave is ongoing with much above-normal temperatures over the Southwest U.S. through this weekend. Periods of critical fire weather will persist from the central Rockies to the central and southern Plains through the weekend as gusty winds and low relative humidity continue. A Kona low will continue to bring several rounds of moderate to heavy rainfall to Hawaii through Sunday. 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

79°F

26°C

Humidity 20%
Wind Speed N 1 MPH
Barometer NA
Dewpoint 35°F (2°C)
Visibility NA
Heat Index78°F (26°C)
Last update 20 Mar 02:35 PM PDT
Extended Forecast for

2 Miles S Clayton CA

Heat Advisory March 20, 04:28pm until March 20, 08:00pm
Click here for hazard details and duration
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  •  
    Heat Advisory March 20, 04:28pm until March 20, 08:00pm

    NOW until 8:00pm Fri

    Heat Advisory

  • Tonight

    Low: 60 °F

    Mostly Clear

  • Saturday

    Saturday: Mostly sunny, with a high near 82. West wind 7 to 13 mph, with gusts as high as 23 mph.

    High: 82 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 54. West southwest wind 9 to 14 mph, with gusts as high as 25 mph.

    Low: 54 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 79. West southwest wind around 7 mph.

    High: 79 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 52. Southwest wind around 9 mph, with gusts as high as 18 mph.

    Low: 52 °F

    Mostly Clear

  • Monday

    Monday: Sunny, with a high near 80.

    High: 80 °F

    Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 54.

    Low: 54 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 81.

    High: 81 °F

    Sunny

Detailed Forecast

Tonight
Mostly clear, with a low around 60. West wind 6 to 9 mph becoming south southwest after midnight.
Saturday
Mostly sunny, with a high near 82. West wind 7 to 13 mph, with gusts as high as 23 mph.
Saturday Night
Mostly clear, with a low around 54. West southwest wind 9 to 14 mph, with gusts as high as 25 mph.
Sunday
Sunny, with a high near 79. West southwest wind around 7 mph.
Sunday Night
Mostly clear, with a low around 52. Southwest wind around 9 mph, with gusts as high as 18 mph.
Monday
Sunny, with a high near 80.
Monday Night
Mostly clear, with a low around 54.
Tuesday
Sunny, with a high near 81.
Tuesday Night
Mostly clear, with a low around 55.
Wednesday
Sunny, with a high near 78.
Wednesday Night
Mostly clear, with a low around 53.
Thursday
Mostly sunny, with a high near 78.
Thursday Night
Partly cloudy, with a low around 54.
Friday
Mostly sunny, with a high near 78.
Basemap Options
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ABOUT THIS FORECAST

 
Point Forecast:
2 Miles S Clayton CA
 37.92°N 121.93°W (Elev. 600 ft)
2:07 pm PDT Mar 20, 2026
4pm PDT Mar 20, 2026-6pm PDT Mar 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