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

Prolonged Atmospheric River Will Impact the Northwest Early this Week

A weather system in the Pacific Northwest will produce rain throughout the day, before a potent atmospheric river produces a prolonged round of heavy rainfall, widespread urban and river flooding, and high elevation snow to the region Monday through Wednesday. Showers and thunderstorms may produce isolated damaging winds, a brief tornado, and locally heavy rainfall across parts of Florida today. Read More >

Current conditions at

LAS TRAMPAS (LTRC1)

Lat: 37.83389°NLon: 122.06694°WElev: 1760.0ft.

NA

50°F

10°C

Humidity 62%
Wind Speed NE 9 MPH
Barometer NA
Dewpoint 37°F (3°C)
Visibility NA
Wind Chill46°F (8°C)
Last update 07 Dec 05:28 PM PST
Extended Forecast for

San Ramon CA

  • Tonight

    Tonight: Widespread dense fog, mainly between 7pm and 4am. Otherwise, mostly clear, with a low around 40. Calm wind.

    Low: 40 °F

    Dense Fog

  • Monday

    Monday: Widespread dense fog, mainly before 10am. Otherwise, sunny, with a high near 59. Calm wind.

    High: 59 °F

    Dense Fog
    then Sunny

  • Monday Night

    Monday Night: Patchy fog after 9pm. Otherwise, mostly clear, with a low around 41. Calm wind.

    Low: 41 °F

    Patchy Fog

  • Tuesday

    Tuesday: Widespread fog, mainly before 8am. Otherwise, sunny, with a high near 62. Calm wind.

    High: 62 °F

    Fog then
    Sunny

  • Tuesday Night

    Tuesday Night: Patchy fog. Otherwise, mostly clear, with a low around 43. Calm wind.

    Low: 43 °F

    Patchy Fog

  • Wednesday

    Wednesday: Areas of fog before 10am. Otherwise, sunny, with a high near 65.

    High: 65 °F

    Areas Fog
    then Sunny

  • Wednesday Night

    Wednesday Night: Patchy fog after 10pm. Otherwise, mostly clear, with a low around 44.

    Low: 44 °F

    Patchy Fog

  • Thursday

    Thursday: Widespread fog, mainly before 8am. Otherwise, sunny, with a high near 65.

    High: 65 °F

    Fog then
    Sunny

  • Thursday Night

    Thursday Night: Patchy fog after 2am. Otherwise, mostly clear, with a low around 43.

    Low: 43 °F

    Clear then
    Patchy Fog

Detailed Forecast

Tonight
Widespread dense fog, mainly between 7pm and 4am. Otherwise, mostly clear, with a low around 40. Calm wind.
Monday
Widespread dense fog, mainly before 10am. Otherwise, sunny, with a high near 59. Calm wind.
Monday Night
Patchy fog after 9pm. Otherwise, mostly clear, with a low around 41. Calm wind.
Tuesday
Widespread fog, mainly before 8am. Otherwise, sunny, with a high near 62. Calm wind.
Tuesday Night
Patchy fog. Otherwise, mostly clear, with a low around 43. Calm wind.
Wednesday
Areas of fog before 10am. Otherwise, sunny, with a high near 65.
Wednesday Night
Patchy fog after 10pm. Otherwise, mostly clear, with a low around 44.
Thursday
Widespread fog, mainly before 8am. Otherwise, sunny, with a high near 65.
Thursday Night
Patchy fog after 2am. Otherwise, mostly clear, with a low around 43.
Friday
Areas of fog before 11am. Otherwise, sunny, with a high near 64.
Friday Night
Patchy fog. Otherwise, mostly clear, with a low around 43.
Saturday
Areas of fog. Otherwise, sunny, with a high near 64.
Saturday Night
Patchy fog. Otherwise, partly cloudy, with a low around 43.
Sunday
Areas of fog. Otherwise, mostly sunny, with a high near 62.
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ABOUT THIS FORECAST

 
Point Forecast:
San Ramon CA
 37.76°N 121.95°W (Elev. 420 ft)
Last Update:
5:02 pm PST Dec 7, 2025
Forecast Valid:
5pm PST Dec 7, 2025-6pm PST Dec 14, 2025
 
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Additional Resources

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