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

Atmospheric River Bringing Heavy Rain to Southern California and Heavy Snow to the Sierra Nevadas

A strong atmospheric river will continue heavy rain over southern California through Friday. The heaviest rainfall is ongoing today in the Los Angeles Basin. Flash and urban flooding is possible. A prolonged heavy snowfall has begun over the Sierra Nevada Mountains and will continue through Friday. Travel will become increasingly difficult over the passes due to snow and strong winds. Read More >

Hazardous Weather Conditions

Current conditions at

Hayward, Hayward Air Terminal (KHWD)

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

Mostly Cloudy

57°F

14°C

Humidity 87%
Wind Speed SW 16 MPH
Barometer 29.59 in (1002.03 mb)
Dewpoint 54°F (12°C)
Visibility 10.00 mi
Last update 24 Dec 05:00 AM PST
Extended Forecast for

2 Miles NNW Castro Valley CA

Flood Watch December 24, 05:22am until December 26, 10:00pm
Wind Advisory December 24, 08:00pm until December 25, 10:00am
Wind Advisory December 24, 05:22am until December 24, 08:00am
Flood Advisory December 24, 05:22am until December 24, 06:15am
Click here for hazard details and duration
Flood Watch
Wind Advisory
Wind Advisory
Flood Advisory
  •  
    Flood Watch December 24, 05:22am until December 26, 10:00pm
    Wind Advisory December 24, 05:22am until December 24, 08:00am
    Flood Advisory December 24, 05:22am until December 24, 06:15am

    NOW: Multiple hazards in effect

    Click HERE for Details

  • Overnight

    Low: 52 °F

    Showers
    Likely

  • Wednesday

    Wednesday: Showers likely before 4pm, then a chance of showers and thunderstorms between 4pm and 5pm, then showers and possibly a thunderstorm after 5pm. Some of the storms could be severe. High near 60. South southeast wind 6 to 11 mph, with gusts as high as 23 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 60 °F

    Showers
    Likely then
    Severe
    Thunderstorms

  • Wednesday Night

    Wednesday Night: Showers and thunderstorms likely before 10pm, then a chance of showers between 10pm and 1am, then showers and possibly a thunderstorm after 1am. Some of the storms could be severe. Steady temperature around 53. Breezy, with a south southeast wind 15 to 22 mph, with gusts as high as 44 mph. Chance of precipitation is 90%. New rainfall amounts between a half and three quarters of an inch possible.

    Low: 53 °F

    Severe
    Thunderstorms
    and Breezy

  • Christmas Day

    Christmas Day: Showers and possibly a thunderstorm. Some of the storms could be severe. High near 56. South wind 16 to 21 mph, with gusts as high as 41 mph. Chance of precipitation is 100%. New precipitation amounts between a quarter and half of an inch possible.

    High: 56 °F

    Severe
    Thunderstorms
    then Showers

  • Thursday Night

    Thursday Night: Showers and possibly a thunderstorm. Some of the storms could be severe. Low around 48. South wind 14 to 16 mph, with gusts as high as 30 mph. Chance of precipitation is 100%. New rainfall amounts between a quarter and half of an inch possible.

    Low: 48 °F

    Severe
    Thunderstorms

  • Friday

    Friday: Showers, with thunderstorms also possible after 4pm. High near 56. Chance of precipitation is 90%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 56 °F

    Showers

  • Friday Night

    Friday Night: Showers likely and possibly a thunderstorm before 7pm, then showers likely between 7pm and 10pm, then a chance of showers and thunderstorms after 10pm. Patchy fog. Otherwise, mostly cloudy, with a low around 43. Chance of precipitation is 60%.

    Low: 43 °F

    Showers
    Likely and
    Patchy Fog

  • Saturday

    Saturday: A chance of showers, mainly before 10am. Areas of fog before noon. Otherwise, partly sunny, with a high near 54.

    High: 54 °F

    Chance
    Showers and
    Areas Fog

Detailed Forecast

Overnight
Showers likely. Cloudy, with a low around 52. Southwest wind around 17 mph, with gusts as high as 37 mph. Chance of precipitation is 60%.
Wednesday
Showers likely before 4pm, then a chance of showers and thunderstorms between 4pm and 5pm, then showers and possibly a thunderstorm after 5pm. Some of the storms could be severe. High near 60. South southeast wind 6 to 11 mph, with gusts as high as 23 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Wednesday Night
Showers and thunderstorms likely before 10pm, then a chance of showers between 10pm and 1am, then showers and possibly a thunderstorm after 1am. Some of the storms could be severe. Steady temperature around 53. Breezy, with a south southeast wind 15 to 22 mph, with gusts as high as 44 mph. Chance of precipitation is 90%. New rainfall amounts between a half and three quarters of an inch possible.
Christmas Day
Showers and possibly a thunderstorm. Some of the storms could be severe. High near 56. South wind 16 to 21 mph, with gusts as high as 41 mph. Chance of precipitation is 100%. New precipitation amounts between a quarter and half of an inch possible.
Thursday Night
Showers and possibly a thunderstorm. Some of the storms could be severe. Low around 48. South wind 14 to 16 mph, with gusts as high as 30 mph. Chance of precipitation is 100%. New rainfall amounts between a quarter and half of an inch possible.
Friday
Showers, with thunderstorms also possible after 4pm. High near 56. Chance of precipitation is 90%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Friday Night
Showers likely and possibly a thunderstorm before 7pm, then showers likely between 7pm and 10pm, then a chance of showers and thunderstorms after 10pm. Patchy fog. Otherwise, mostly cloudy, with a low around 43. Chance of precipitation is 60%.
Saturday
A chance of showers, mainly before 10am. Areas of fog before noon. Otherwise, partly sunny, with a high near 54.
Saturday Night
Mostly clear, with a low around 37.
Sunday
Sunny, with a high near 53.
Sunday Night
Mostly clear, with a low around 36.
Monday
Patchy fog. Otherwise, sunny, with a high near 55.
Monday Night
Mostly clear, with a low around 38.
Tuesday
Mostly sunny, with a high near 57.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
2 Miles NNW Castro Valley CA
 37.73°N 122.08°W (Elev. 614 ft)
Last Update:
4:29 am PST Dec 24, 2025
Forecast Valid:
5am PST Dec 24, 2025-6pm PST Dec 30, 2025
 
Forecast Discussion
 
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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