Dangerous Heat in the Southwest; Severe Thunderstorms and Heavy Rain in the Northeast and Mid-Atlantic

Dangerous heat will persist across the Southwest U.S. through Friday with daytime highs of 110-115°F. Heat across the southern Plains will briefly ease to near-normal by late week. Strong to severe thunderstorms may produce damaging wind, hail, a tornado or two, heavy rain and flash flooding across parts of the Mid-Atlantic and Northeast. Heavy rainfall threat continues across the Gulf Coast. Read More >

Current conditions at

LOS ALTOS (LOAC1)

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

NA

77°F

25°C

Humidity 58%
Wind Speed NE 1 MPH
Barometer NA
Dewpoint 61°F (16°C)
Visibility NA
Heat Index79°F (26°C)
Last update 27 Aug 09:10 AM PDT
Extended Forecast for

Portola Valley CA

  • Today

    Today: A 20 percent chance of showers.  Partly sunny, with a high near 85. Light and variable wind.

    High: 85 °F

    Slight Chance
    Showers

  • Tonight

    Tonight: A 20 percent chance of showers.  Mostly cloudy, with a low around 59. South southwest wind 5 to 8 mph becoming calm  after midnight.

    Low: 59 °F

    Slight Chance
    Showers

  • Friday

    Friday: A 20 percent chance of showers.  Mostly cloudy, with a high near 78. Calm wind.

    High: 78 °F

    Slight Chance
    Showers

  • Friday Night

    Friday Night: Mostly cloudy during the early evening, then becoming mostly clear, with a low around 54. Southwest wind 5 to 9 mph becoming light and variable  after midnight.

    Low: 54 °F

    Mostly Clear

  • Saturday

    Saturday: Mostly sunny, with a high near 74. West northwest wind 3 to 7 mph.

    High: 74 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 52.

    Low: 52 °F

    Mostly Clear

  • Sunday

    Sunday: Mostly sunny, with a high near 74.

    High: 74 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 52.

    Low: 52 °F

    Mostly Clear

  • Monday

    Monday: Mostly sunny, with a high near 71.

    High: 71 °F

    Mostly Sunny

Detailed Forecast

Today
A 20 percent chance of showers. Partly sunny, with a high near 85. Light and variable wind.
Tonight
A 20 percent chance of showers. Mostly cloudy, with a low around 59. South southwest wind 5 to 8 mph becoming calm after midnight.
Friday
A 20 percent chance of showers. Mostly cloudy, with a high near 78. Calm wind.
Friday Night
Mostly cloudy during the early evening, then becoming mostly clear, with a low around 54. Southwest wind 5 to 9 mph becoming light and variable after midnight.
Saturday
Mostly sunny, with a high near 74. West northwest wind 3 to 7 mph.
Saturday Night
Mostly clear, with a low around 52.
Sunday
Mostly sunny, with a high near 74.
Sunday Night
Mostly clear, with a low around 52.
Monday
Mostly sunny, with a high near 71.
Monday Night
Partly cloudy, with a low around 52.
Tuesday
Mostly sunny, with a high near 73.
Tuesday Night
Partly cloudy, with a low around 53.
Wednesday
Mostly sunny, with a high near 76.
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ABOUT THIS FORECAST

 
Point Forecast:
Portola Valley CA
 37.37°N 122.22°W (Elev. 597 ft)
6:47 am PDT Aug 27, 2026
10am PDT Aug 27, 2026-6pm PDT Sep 2, 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