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

Hayward, Hayward Air Terminal (KHWD)

Lat: 37.66083°NLon: 122.11833°WElev: 46.0ft.

Clear

52°F

11°C

Humidity 81%
Wind Speed W 6 MPH
Barometer 30.25 in (1024.38 mb)
Dewpoint 46°F (8°C)
Visibility 7.00 mi
Last update 07 Dec 02:35 PM PST
Extended Forecast for

2 Miles NNW Castro Valley CA

  • This Afternoon

    This Afternoon: Mostly sunny, with a high near 59. North northwest wind 3 to 5 mph.

    High: 59 °F

    Mostly Sunny

  • Tonight

    Tonight: Patchy fog before 2am, then patchy fog after 4am. Otherwise, mostly clear, with a low around 41. Calm wind.

    Low: 41 °F

    Mostly Clear
    then Patchy
    Fog

  • Monday

    Monday: Patchy dense fog before 9am. Otherwise, sunny, with a high near 62. Calm wind becoming north northwest around 5 mph in the afternoon.

    High: 62 °F

    Patchy Dense
    Fog then
    Sunny

  • Monday Night

    Monday Night: Patchy fog after 4am. Otherwise, mostly clear, with a low around 43. Calm wind.

    Low: 43 °F

    Mostly Clear
    then Patchy
    Fog

  • Tuesday

    Tuesday: Patchy fog before 8am. Otherwise, sunny, with a high near 62. Calm wind becoming north northwest around 5 mph in the afternoon.

    High: 62 °F

    Patchy Fog
    then Sunny

  • Tuesday Night

    Tuesday Night: Patchy fog after 5am. Otherwise, mostly clear, with a low around 45.

    Low: 45 °F

    Mostly Clear
    then Patchy
    Fog

  • Wednesday

    Wednesday: Patchy fog before 8am. Otherwise, sunny, with a high near 65.

    High: 65 °F

    Patchy Fog
    then Sunny

  • Wednesday Night

    Wednesday Night: Patchy fog after 5am. Otherwise, mostly clear, with a low around 45.

    Low: 45 °F

    Mostly Clear
    then Patchy
    Fog

  • Thursday

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

    High: 65 °F

    Patchy Fog
    then Sunny

Detailed Forecast

This Afternoon
Mostly sunny, with a high near 59. North northwest wind 3 to 5 mph.
Tonight
Patchy fog before 2am, then patchy fog after 4am. Otherwise, mostly clear, with a low around 41. Calm wind.
Monday
Patchy dense fog before 9am. Otherwise, sunny, with a high near 62. Calm wind becoming north northwest around 5 mph in the afternoon.
Monday Night
Patchy fog after 4am. Otherwise, mostly clear, with a low around 43. Calm wind.
Tuesday
Patchy fog before 8am. Otherwise, sunny, with a high near 62. Calm wind becoming north northwest around 5 mph in the afternoon.
Tuesday Night
Patchy fog after 5am. Otherwise, mostly clear, with a low around 45.
Wednesday
Patchy fog before 8am. Otherwise, sunny, with a high near 65.
Wednesday Night
Patchy fog after 5am. Otherwise, mostly clear, with a low around 45.
Thursday
Patchy fog before 8am. Otherwise, sunny, with a high near 65.
Thursday Night
Mostly clear, with a low around 44.
Friday
Sunny, with a high near 64.
Friday Night
Mostly clear, with a low around 44.
Saturday
Sunny, with a high near 64.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
2 Miles NNW Castro Valley CA
 37.73°N 122.08°W (Elev. 614 ft)
Last Update:
12:41 pm PST Dec 7, 2025
Forecast Valid:
2pm PST Dec 7, 2025-6pm PST Dec 13, 2025
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

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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