Severe Weather and Heavy Rain from the Great Lakes to the Mid-Atlantic; Heat Persists in the East

Widespread strong thunderstorms with damaging winds and locally heavy rain are expected from the Upper Ohio Valley into the southern Mid-Atlantic today and portions of the central Appalachians and Carolinas on Saturday. Monsoonal moisture will bring a flash flooding threat to the Desert Southwest. Sweltering heat persists from the Plains to the southern Mid-Atlantic through tonight. Read More >

Current conditions at

LOS ALTOS (LOAC1)

Lat: 37.35472°NLon: 122.14167°WElev: 539.0ft.

NA

67°F

19°C

Humidity 52%
Wind Speed NW 1 MPH
Barometer NA
Dewpoint 49°F (9°C)
Visibility NA
Last update 04 Sep 07:10 PM PDT
Extended Forecast for

Portola Valley CA

  • Tonight

    Tonight: Mostly clear, with a low around 52. West wind 5 to 9 mph becoming calm  in the evening.

    Low: 52 °F

    Mostly Clear

  • Saturday

    Saturday: Patchy fog before 8am.  Otherwise, sunny, with a high near 77. Calm wind becoming west 5 to 9 mph in the afternoon. Winds could gust as high as 18 mph.

    High: 77 °F

    Patchy Fog
    then Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 52. West wind 5 to 9 mph becoming calm  in the evening. Winds could gust as high as 18 mph.

    Low: 52 °F

    Partly Cloudy

  • Sunday

    Sunday: Patchy fog before 8am.  Otherwise, partly sunny, then gradually becoming sunny, with a high near 74. Calm wind becoming west northwest 5 to 9 mph in the afternoon. Winds could gust as high as 18 mph.

    High: 74 °F

    Patchy Fog
    then Sunny

  • Sunday Night

    Sunday Night: Patchy fog after 5am.  Otherwise, mostly clear, with a low around 52. West northwest wind 8 to 13 mph becoming light  after midnight. Winds could gust as high as 23 mph.

    Low: 52 °F

    Clear then
    Patchy Fog

  • Labor Day

    Labor Day: Patchy fog before 8am.  Otherwise, sunny, with a high near 85.

    High: 85 °F

    Patchy Fog
    then Sunny

  • Monday Night

    Monday Night: Clear, with a low around 56.

    Low: 56 °F

    Clear

  • Tuesday

    Tuesday: Sunny, with a high near 87.

    High: 87 °F

    Sunny

  • Tuesday Night

    Tuesday Night: A slight chance of rain after 11pm.  Partly cloudy, with a low around 58.

    Low: 58 °F

    Slight Chance
    Rain

Detailed Forecast

Tonight
Mostly clear, with a low around 52. West wind 5 to 9 mph becoming calm in the evening.
Saturday
Patchy fog before 8am. Otherwise, sunny, with a high near 77. Calm wind becoming west 5 to 9 mph in the afternoon. Winds could gust as high as 18 mph.
Saturday Night
Partly cloudy, with a low around 52. West wind 5 to 9 mph becoming calm in the evening. Winds could gust as high as 18 mph.
Sunday
Patchy fog before 8am. Otherwise, partly sunny, then gradually becoming sunny, with a high near 74. Calm wind becoming west northwest 5 to 9 mph in the afternoon. Winds could gust as high as 18 mph.
Sunday Night
Patchy fog after 5am. Otherwise, mostly clear, with a low around 52. West northwest wind 8 to 13 mph becoming light after midnight. Winds could gust as high as 23 mph.
Labor Day
Patchy fog before 8am. Otherwise, sunny, with a high near 85.
Monday Night
Clear, with a low around 56.
Tuesday
Sunny, with a high near 87.
Tuesday Night
A slight chance of rain after 11pm. Partly cloudy, with a low around 58.
Wednesday
A slight chance of rain. Partly sunny, with a high near 83.
Wednesday Night
A chance of rain. Mostly cloudy, with a low around 60.
Thursday
A slight chance of rain. Mostly sunny, with a high near 84.
Thursday Night
Partly cloudy, with a low around 58.
Friday
Mostly sunny, with a high near 79.
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ABOUT THIS FORECAST

 
Point Forecast:
Portola Valley CA
 37.39°N 122.23°W (Elev. 397 ft)
1:26 pm PDT Sep 4, 2026
7pm PDT Sep 4, 2026-6pm PDT Sep 11, 2026
 
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Additional Resources

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