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

Cold Front Moving Through the Northeast U.S. Monday; Atmospheric River to Impact the Pacific Northwest Midweek

A cold front will cross the Great Lakes and Northeast U.S. through Monday with gusty winds and areas of rain showers. A strong atmospheric river is expected to move into the Pacific Northwest by midweek bringing a threat for moderate to heavy rainfall, gusty winds, and mountain snows for parts of Washington, Oregon, northern California, and the Sierra Nevada. Read More >

Current conditions at

LOS ALTOS (LOAC1)

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

NA

80°F

27°C

Humidity 41%
Wind Speed NE 1 MPH
Barometer NA
Dewpoint 54°F (12°C)
Visibility NA
Heat Index80°F (27°C)
Last update 02 Nov 01:10 PM PST
Extended Forecast for

Portola Valley CA

  • This Afternoon

    This Afternoon: Sunny, with a high near 77. North wind around 6 mph.

    High: 77 °F

    Sunny

  • Tonight

    Tonight: Patchy fog after 5am. Otherwise, mostly clear, with a low around 50. Calm wind becoming southwest 5 to 7 mph after midnight.

    Low: 50 °F

    Mostly Clear
    then Patchy
    Fog

  • Monday

    Monday: Patchy fog before 7am. Otherwise, sunny, with a high near 72. Light and variable wind becoming west southwest 9 to 14 mph in the afternoon.

    High: 72 °F

    Patchy Fog
    then Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 50. South southwest wind 7 to 9 mph.

    Low: 50 °F

    Mostly Clear

  • Tuesday

    Tuesday: Mostly sunny, with a high near 74. South southwest wind 6 to 11 mph increasing to 12 to 17 mph in the afternoon.

    High: 74 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Rain, mainly after 4am. Low around 55. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.

    Low: 55 °F

    Chance Rain
    then Rain

  • Wednesday

    Wednesday: Rain, mainly before 4pm. High near 68. Breezy. Chance of precipitation is 90%.

    High: 68 °F

    Rain and
    Breezy

  • Wednesday Night

    Wednesday Night: A chance of rain before 10pm. Patchy fog after 5am. Otherwise, mostly cloudy, with a low around 52.

    Low: 52 °F

    Chance Rain
    then Patchy
    Fog

  • Thursday

    Thursday: Areas of fog before 9am. Otherwise, mostly sunny, with a high near 71.

    High: 71 °F

    Areas Fog
    then Sunny

Detailed Forecast

This Afternoon
Sunny, with a high near 77. North wind around 6 mph.
Tonight
Patchy fog after 5am. Otherwise, mostly clear, with a low around 50. Calm wind becoming southwest 5 to 7 mph after midnight.
Monday
Patchy fog before 7am. Otherwise, sunny, with a high near 72. Light and variable wind becoming west southwest 9 to 14 mph in the afternoon.
Monday Night
Mostly clear, with a low around 50. South southwest wind 7 to 9 mph.
Tuesday
Mostly sunny, with a high near 74. South southwest wind 6 to 11 mph increasing to 12 to 17 mph in the afternoon.
Tuesday Night
Rain, mainly after 4am. Low around 55. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.
Wednesday
Rain, mainly before 4pm. High near 68. Breezy. Chance of precipitation is 90%.
Wednesday Night
A chance of rain before 10pm. Patchy fog after 5am. Otherwise, mostly cloudy, with a low around 52.
Thursday
Areas of fog before 9am. Otherwise, mostly sunny, with a high near 71.
Thursday Night
Partly cloudy, with a low around 52.
Friday
Mostly sunny, with a high near 73.
Friday Night
Patchy fog. Otherwise, partly cloudy, with a low around 52.
Saturday
Patchy fog. Otherwise, mostly sunny, with a high near 75.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Portola Valley CA
 37.39°N 122.23°W (Elev. 397 ft)
Last Update:
12:59 pm PST Nov 2, 2025
Forecast Valid:
2pm PST Nov 2, 2025-6pm PST Nov 8, 2025
 
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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