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

4 Miles SSE Clayton CA

  • Overnight

    Overnight: Mostly clear, with a low around 55. West wind 9 to 14 mph becoming north. Winds could gust as high as 24 mph.

    Low: 55 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 69. North wind 8 to 11 mph becoming west in the afternoon. Winds could gust as high as 22 mph.

    High: 69 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 55. Southwest wind around 15 mph, with gusts as high as 25 mph.

    Low: 55 °F

    Mostly Clear

  • Monday

    Monday: Sunny, with a high near 68. Southwest wind 9 to 14 mph, with gusts as high as 24 mph.

    High: 68 °F

    Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 53. Southwest wind 13 to 15 mph, with gusts as high as 26 mph.

    Low: 53 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 70.

    High: 70 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 53.

    Low: 53 °F

    Mostly Clear

  • Wednesday

    Wednesday: Mostly sunny, with a high near 68.

    High: 68 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 50.

    Low: 50 °F

    Mostly Clear

Detailed Forecast

Overnight
Mostly clear, with a low around 55. West wind 9 to 14 mph becoming north. Winds could gust as high as 24 mph.
Sunday
Sunny, with a high near 69. North wind 8 to 11 mph becoming west in the afternoon. Winds could gust as high as 22 mph.
Sunday Night
Mostly clear, with a low around 55. Southwest wind around 15 mph, with gusts as high as 25 mph.
Monday
Sunny, with a high near 68. Southwest wind 9 to 14 mph, with gusts as high as 24 mph.
Monday Night
Mostly clear, with a low around 53. Southwest wind 13 to 15 mph, with gusts as high as 26 mph.
Tuesday
Sunny, with a high near 70.
Tuesday Night
Mostly clear, with a low around 53.
Wednesday
Mostly sunny, with a high near 68.
Wednesday Night
Mostly clear, with a low around 50.
Thursday
Mostly sunny, with a high near 68.
Thursday Night
Partly cloudy, with a low around 51.
Friday
Mostly sunny, with a high near 68.
Friday Night
Partly cloudy, with a low around 52.
Saturday
Mostly sunny, with a high near 69.
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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:
8:26 pm PDT Mar 21, 2026
Forecast Valid:
12am PDT Mar 22, 2026-6pm PDT Mar 28, 2026
 
Forecast Discussion
 
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Additional Resources

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Chance of Precipitation