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

SJSU - Mount Diablo Summit Museum Rooftop (SJS02)

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

NA

31°F

-1°C

Humidity 100%
Wind Speed N 0 MPH
Barometer NA
Dewpoint 31°F (-1°C)
Visibility NA
Last update 17 Feb 07:20 PM PST
Extended Forecast for

4 Miles S Clayton CA

  • Tonight

    Tonight: Snow likely before 2am, then a slight chance of snow after 3am. Mostly cloudy, with a steady temperature around 35. West northwest wind 11 to 17 mph, with gusts as high as 39 mph. Chance of precipitation is 60%. Total nighttime snow accumulation of less than one inch possible.

    Low: 35 °F

    Snow Likely
    then Slight
    Chance Snow

  • Wednesday

    Wednesday: A 40 percent chance of snow before 4pm. Partly sunny, with a high near 40. West southwest wind around 11 mph, with gusts as high as 28 mph. New snow accumulation of less than one inch possible.

    High: 40 °F

    Chance Snow

  • Wednesday Night

    Wednesday Night: Snow before 1am, then rain and snow. Temperature rising to around 40 by 5am. South wind around 13 mph, with gusts as high as 33 mph. Chance of precipitation is 90%. New snow accumulation of less than one inch possible.

    Low: 37 °F⇑

    Snow then
    Rain/Snow

  • Thursday

    Thursday: Rain and snow, becoming all snow after 7am. High near 41. Breezy, with a southwest wind 11 to 16 mph becoming west northwest 18 to 23 mph in the morning. Winds could gust as high as 44 mph. Chance of precipitation is 90%. Little or no snow accumulation expected.

    High: 41 °F

    Breezy.
    Rain/Snow
    then Chance
    Snow

  • Thursday Night

    Thursday Night: A 30 percent chance of snow before 10pm. Partly cloudy, with a low around 34. West northwest wind 6 to 14 mph, with gusts as high as 32 mph. Little or no snow accumulation expected.

    Low: 34 °F

    Chance Snow
    then Mostly
    Clear

  • Friday

    Friday: A slight chance of snow between 10am and 4pm. Mostly sunny, with a high near 45. Chance of precipitation is 20%.

    High: 45 °F

    Slight Chance
    Snow

  • Friday Night

    Friday Night: A chance of rain and snow, mainly between 10pm and 4am. Partly cloudy, with a low around 37. Chance of precipitation is 30%. Little or no snow accumulation expected.

    Low: 37 °F

    Chance
    Rain/Snow

  • Saturday

    Saturday: A slight chance of rain and snow before 10am, then a chance of rain. Partly sunny, with a high near 50.

    High: 50 °F

    Chance
    Rain/Snow
    then Chance
    Rain

  • Saturday Night

    Saturday Night: Rain likely, mainly after 10pm. Mostly cloudy, with a low around 46. Breezy.

    Low: 46 °F

    Rain Likely
    and Breezy

Detailed Forecast

Tonight
Snow likely before 2am, then a slight chance of snow after 3am. Mostly cloudy, with a steady temperature around 35. West northwest wind 11 to 17 mph, with gusts as high as 39 mph. Chance of precipitation is 60%. Total nighttime snow accumulation of less than one inch possible.
Wednesday
A 40 percent chance of snow before 4pm. Partly sunny, with a high near 40. West southwest wind around 11 mph, with gusts as high as 28 mph. New snow accumulation of less than one inch possible.
Wednesday Night
Snow before 1am, then rain and snow. Temperature rising to around 40 by 5am. South wind around 13 mph, with gusts as high as 33 mph. Chance of precipitation is 90%. New snow accumulation of less than one inch possible.
Thursday
Rain and snow, becoming all snow after 7am. High near 41. Breezy, with a southwest wind 11 to 16 mph becoming west northwest 18 to 23 mph in the morning. Winds could gust as high as 44 mph. Chance of precipitation is 90%. Little or no snow accumulation expected.
Thursday Night
A 30 percent chance of snow before 10pm. Partly cloudy, with a low around 34. West northwest wind 6 to 14 mph, with gusts as high as 32 mph. Little or no snow accumulation expected.
Friday
A slight chance of snow between 10am and 4pm. Mostly sunny, with a high near 45. Chance of precipitation is 20%.
Friday Night
A chance of rain and snow, mainly between 10pm and 4am. Partly cloudy, with a low around 37. Chance of precipitation is 30%. Little or no snow accumulation expected.
Saturday
A slight chance of rain and snow before 10am, then a chance of rain. Partly sunny, with a high near 50.
Saturday Night
Rain likely, mainly after 10pm. Mostly cloudy, with a low around 46. Breezy.
Sunday
Rain likely. Mostly cloudy, with a high near 54. Breezy.
Sunday Night
Rain. Cloudy, with a low around 51. Breezy.
Monday
Rain. Cloudy, with a high near 55. Breezy.
Monday Night
Rain. Cloudy, with a low around 51.
Tuesday
Rain. Cloudy, with a high near 54.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
4 Miles S Clayton CA
 37.87°N 121.92°W (Elev. 2818 ft)
Last Update:
2:05 pm PST Feb 17, 2026
Forecast Valid:
7pm PST Feb 17, 2026-6pm PST Feb 24, 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