Prolonged Atmospheric River in the Northwest; Snow in the North-Central US

A prolonged atmospheric river will bring heavy rainfall which may lead to widespread urban and river flooding, heavy mountain snow, along with gusty winds to the Pacific Northwest into the northern Rockies through much of the week. A clipper will bring a period of snow across the upper Midwest and the Great Lakes into Tuesday, before a stronger system bring more wintry impacts. Read More >

Current conditions at

Hayward, Hayward Air Terminal (KHWD)

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

Clear

43°F

6°C

Humidity 93%
Wind Speed NE 9 MPH
Barometer 30.29 in (1025.74 mb)
Dewpoint 41°F (5°C)
Visibility 7.00 mi
Wind Chill38°F (3°C)
Last update 09 Dec 02:00 AM PST
Extended Forecast for

Castro Valley CA

  • Overnight

    Overnight: Mostly clear, with a low around 43. Calm wind.

    Low: 43 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 64. Calm wind becoming north northeast around 5 mph in the afternoon.

    High: 64 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Clear, with a low around 44. Calm wind.

    Low: 44 °F

    Clear

  • Wednesday

    Wednesday: Sunny, with a high near 67. Calm wind becoming north northeast around 6 mph in the morning.

    High: 67 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 46. Calm wind.

    Low: 46 °F

    Mostly Clear

  • Thursday

    Thursday: Sunny, with a high near 67.

    High: 67 °F

    Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 45.

    Low: 45 °F

    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 65.

    High: 65 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 44.

    Low: 44 °F

    Mostly Clear

Detailed Forecast

Overnight
Mostly clear, with a low around 43. Calm wind.
Tuesday
Sunny, with a high near 64. Calm wind becoming north northeast around 5 mph in the afternoon.
Tuesday Night
Clear, with a low around 44. Calm wind.
Wednesday
Sunny, with a high near 67. Calm wind becoming north northeast around 6 mph in the morning.
Wednesday Night
Mostly clear, with a low around 46. Calm wind.
Thursday
Sunny, with a high near 67.
Thursday Night
Mostly clear, with a low around 45.
Friday
Sunny, with a high near 65.
Friday Night
Mostly clear, with a low around 44.
Saturday
Mostly sunny, with a high near 63.
Saturday Night
Partly cloudy, with a low around 45.
Sunday
Mostly sunny, with a high near 62.
Sunday Night
Mostly cloudy, with a low around 46.
Monday
A slight chance of rain. Partly sunny, with a high near 63.
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ABOUT THIS FORECAST

 
Point Forecast:
Castro Valley CA
 37.71°N 122.08°W (Elev. 397 ft)
12:26 am PST Dec 9, 2025
2am PST Dec 9, 2025-6pm PST Dec 15, 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