Extreme Heat Across the Southern U.S.; Flash Flooding Threats in the Mid-Atlantic, Northeast, and Four Corners Region

Dangerous and extreme heat will remain across portions of the southern U.S. this week. Heavy rainfall may bring significant flash flooding across portions of the Mid-Atlantic and Northeast through the night, and additional flash flooding concerns across New England on Wednesday. Monsoonal thunderstorms will bring a flash flood risk to the Four Corners region, especially in burn scar areas Read More >

Current conditions at

Hayward, Hayward Air Terminal (KHWD)

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

Mostly Cloudy

59°F

15°C

Humidity 87%
Wind Speed WNW 4 MPH
Barometer 29.88 in (1011.85 mb)
Dewpoint 55°F (13°C)
Visibility 10.00 mi
Last update 29 Jul 05:00 AM PDT
Extended Forecast for

Castro Valley CA

  • Today

    Today: Partly sunny, then gradually becoming sunny, with a high near 78. West southwest wind 6 to 9 mph.

    High: 78 °F

    Becoming
    Sunny

  • Tonight

    Tonight: Increasing clouds, with a low around 57. South southwest wind 6 to 8 mph.

    Low: 57 °F

    Increasing
    Clouds

  • Thursday

    Thursday: Mostly sunny, with a high near 79. West southwest wind 5 to 9 mph.

    High: 79 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 57. South southwest wind 5 to 9 mph.

    Low: 57 °F

    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 84. West southwest wind 3 to 8 mph.

    High: 84 °F

    Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 58.

    Low: 58 °F

    Partly Cloudy

  • Saturday

    Saturday: Mostly sunny, with a high near 86.

    High: 86 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 58.

    Low: 58 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 86.

    High: 86 °F

    Sunny

Detailed Forecast

Today
Partly sunny, then gradually becoming sunny, with a high near 78. West southwest wind 6 to 9 mph.
Tonight
Increasing clouds, with a low around 57. South southwest wind 6 to 8 mph.
Thursday
Mostly sunny, with a high near 79. West southwest wind 5 to 9 mph.
Thursday Night
Mostly clear, with a low around 57. South southwest wind 5 to 9 mph.
Friday
Sunny, with a high near 84. West southwest wind 3 to 8 mph.
Friday Night
Partly cloudy, with a low around 58.
Saturday
Mostly sunny, with a high near 86.
Saturday Night
Mostly clear, with a low around 58.
Sunday
Sunny, with a high near 86.
Sunday Night
Mostly clear, with a low around 58.
Monday
Sunny, with a high near 84.
Monday Night
Mostly clear, with a low around 59.
Tuesday
Mostly sunny, with a high near 83.
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ABOUT THIS FORECAST

 
Point Forecast:
Castro Valley CA
 37.71°N 122.08°W (Elev. 397 ft)
1:26 am PDT Jul 29, 2026
5am PDT Jul 29, 2026-6pm PDT Aug 4, 2026
 
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Additional Resources

Radar & Satellite Image

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Hourly Weather Forecast

National Digital Forecast Database