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

Severe Weather and Heavy Rainfall in the Ohio Valley; Heat Continuing in the South and Southeast

Severe thunderstorms with damaging wind gusts will be possible from the mid-Mississippi Valley into parts of the Ohio Valley and central Appalachians tonight. Heavy rain associated with these storms may lead to considerable flash and urban flooding impacts across portions of the Ohio Valley. Mid-summer heat persists from the Central Plains to the Southeast. Read More >

Hazardous Weather Conditions

Current conditions at

LOS ALTOS (LOAC1)

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

NA

61°F

16°C

Humidity 88%
Wind Speed ESE 1 MPH
Barometer NA
Dewpoint 57°F (14°C)
Visibility NA
Last update 12 Aug 12:10 AM PDT
Extended Forecast for

3 Miles NW Portola Valley CA

Coastal Flood Advisory August 12, 01:14am until August 13, 02:00am
Click here for hazard details and duration
Coastal Flood Advisory
  •  
    Coastal Flood Advisory August 12, 01:14am until August 13, 02:00am

    NOW until 2:00am Thu

    Coastal Flood Advisory

  • Overnight

    Low: 58 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Mostly cloudy, then gradually becoming sunny, with a high near 81. South southwest wind 3 to 6 mph.

    High: 81 °F

    Decreasing
    Clouds

  • Wednesday Night

    Wednesday Night: Mostly cloudy, with a low around 56. Southwest wind around 7 mph.

    Low: 56 °F

    Mostly Cloudy

  • Thursday

    Thursday: Partly sunny, with a high near 73. Southwest wind 6 to 10 mph, with gusts as high as 22 mph.

    High: 73 °F

    Partly Sunny

  • Thursday Night

    Thursday Night: A 20 percent chance of showers. Mostly cloudy, with a low around 55. Southwest wind 5 to 10 mph, with gusts as high as 21 mph.

    Low: 55 °F

    Slight Chance
    Showers

  • Friday

    Friday: Partly sunny, with a high near 73.

    High: 73 °F

    Partly Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 54.

    Low: 54 °F

    Partly Cloudy

  • Saturday

    Saturday: Patchy fog before 9am. Otherwise, mostly sunny, with a high near 75.

    High: 75 °F

    Patchy Fog
    then Mostly
    Sunny

Detailed Forecast

Overnight
Mostly cloudy, with a steady temperature around 58. Light south southwest wind.
Wednesday
Mostly cloudy, then gradually becoming sunny, with a high near 81. South southwest wind 3 to 6 mph.
Wednesday Night
Mostly cloudy, with a low around 56. Southwest wind around 7 mph.
Thursday
Partly sunny, with a high near 73. Southwest wind 6 to 10 mph, with gusts as high as 22 mph.
Thursday Night
A 20 percent chance of showers. Mostly cloudy, with a low around 55. Southwest wind 5 to 10 mph, with gusts as high as 21 mph.
Friday
Partly sunny, with a high near 73.
Friday Night
Partly cloudy, with a low around 54.
Saturday
Patchy fog before 9am. Otherwise, mostly sunny, with a high near 75.
Saturday Night
Partly cloudy, with a low around 54.
Sunday
Patchy fog before 9am. Otherwise, partly sunny, with a high near 76.
Sunday Night
Mostly cloudy, with a low around 53.
Monday
Patchy fog. Otherwise, partly sunny, with a high near 76.
Monday Night
Partly cloudy, with a low around 55.
Tuesday
Partly sunny, with a high near 77.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
3 Miles NW Portola Valley CA
 37.41°N 122.26°W (Elev. 535 ft)
Last Update:
11:27 pm PDT Aug 11, 2026
Forecast Valid:
1am PDT Aug 12, 2026-6pm PDT Aug 18, 2026
 
Forecast Discussion
 
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Additional Resources

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High Temperature

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Chance of Precipitation