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

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 >

Current conditions at

SJSU - Mount Diablo Summit Museum Rooftop (SJS02)

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

NA

67°F

19°C

Humidity 22%
Wind Speed W 9 MPH
Barometer NA
Dewpoint 27°F (-3°C)
Visibility NA
Last update 21 Mar 10:25 PM PDT
Extended Forecast for

Clayton CA

  • Overnight

    Overnight: Mostly clear, with a low around 53. South southwest wind 6 to 9 mph becoming southeast.

    Low: 53 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 77. South southeast wind 5 to 9 mph becoming west northwest in the afternoon.

    High: 77 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 54. South southwest wind 9 to 11 mph, with gusts as high as 20 mph.

    Low: 54 °F

    Mostly Clear

  • Monday

    Monday: Sunny, with a high near 76. West southwest wind 7 to 9 mph.

    High: 76 °F

    Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 55. Southwest wind 9 to 11 mph, with gusts as high as 21 mph.

    Low: 55 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 78.

    High: 78 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 55.

    Low: 55 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny, with a high near 76.

    High: 76 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 51.

    Low: 51 °F

    Mostly Clear

Detailed Forecast

Overnight
Mostly clear, with a low around 53. South southwest wind 6 to 9 mph becoming southeast.
Sunday
Sunny, with a high near 77. South southeast wind 5 to 9 mph becoming west northwest in the afternoon.
Sunday Night
Mostly clear, with a low around 54. South southwest wind 9 to 11 mph, with gusts as high as 20 mph.
Monday
Sunny, with a high near 76. West southwest wind 7 to 9 mph.
Monday Night
Mostly clear, with a low around 55. Southwest wind 9 to 11 mph, with gusts as high as 21 mph.
Tuesday
Sunny, with a high near 78.
Tuesday Night
Mostly clear, with a low around 55.
Wednesday
Sunny, with a high near 76.
Wednesday Night
Mostly clear, with a low around 51.
Thursday
Mostly sunny, with a high near 74.
Thursday Night
Partly cloudy, with a low around 53.
Friday
Mostly sunny, with a high near 76.
Friday Night
Partly cloudy, with a low around 54.
Saturday
Mostly sunny, with a high near 75.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Clayton CA
 37.91°N 121.96°W (Elev. 1299 ft)
Last Update:
12:32 am PDT Mar 22, 2026
Forecast Valid:
12am PDT Mar 22, 2026-6pm PDT Mar 28, 2026
 
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