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 >

Hazardous Weather Conditions

Current conditions at

Hayward, Hayward Air Terminal (KHWD)

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

Clear

52°F

11°C

Humidity 74%
Wind Speed WSW 3 MPH
Barometer 30.27 in (1025.06 mb)
Dewpoint 44°F (7°C)
Visibility 9.00 mi
Last update 07 Dec 12:54 PM PST
Extended Forecast for

2 Miles S Union City CA

Coastal Flood Advisory December 7, 01:08pm until December 7, 03:00pm
Click here for hazard details and duration
Coastal Flood Advisory
  •  
    Coastal Flood Advisory December 7, 01:08pm until December 7, 03:00pm

    NOW until 3:00pm Sun

    Coastal Flood Advisory

  • This Afternoon

    High: 58 °F

    Mostly Sunny

  • Tonight

    Tonight: Patchy fog before 3am, then patchy fog after 4am. Otherwise, mostly clear, with a low around 42. Calm wind.

    Low: 42 °F

    Mostly Clear
    then Patchy
    Fog

  • Monday

    Monday: Patchy dense fog before 10am. Otherwise, sunny, with a high near 62. Calm wind becoming west northwest around 5 mph in the afternoon.

    High: 62 °F

    Patchy Dense
    Fog then
    Sunny

  • Monday Night

    Monday Night: Patchy fog after 3am. Otherwise, mostly clear, with a low around 44. Calm wind.

    Low: 44 °F

    Mostly Clear
    then Patchy
    Fog

  • Tuesday

    Tuesday: Patchy fog before 9am. Otherwise, sunny, with a high near 62. Light and variable wind.

    High: 62 °F

    Patchy Fog
    then Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 46.

    Low: 46 °F

    Mostly Clear

  • Wednesday

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

    High: 65 °F

    Patchy Fog
    then Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 47.

    Low: 47 °F

    Mostly Clear

Detailed Forecast

This Afternoon
Mostly sunny, with a high near 58. West northwest wind around 5 mph.
Tonight
Patchy fog before 3am, then patchy fog after 4am. Otherwise, mostly clear, with a low around 42. Calm wind.
Monday
Patchy dense fog before 10am. Otherwise, sunny, with a high near 62. Calm wind becoming west northwest around 5 mph in the afternoon.
Monday Night
Patchy fog after 3am. Otherwise, mostly clear, with a low around 44. Calm wind.
Tuesday
Patchy fog before 9am. Otherwise, sunny, with a high near 62. Light and variable wind.
Tuesday Night
Mostly clear, with a low around 46.
Wednesday
Patchy fog before 8am. Otherwise, sunny, with a high near 65.
Wednesday Night
Mostly clear, with a low around 47.
Thursday
Patchy fog between 7am and 8am. Otherwise, sunny, with a high near 66.
Thursday Night
Mostly clear, with a low around 46.
Friday
Sunny, with a high near 66.
Friday Night
Mostly clear, with a low around 45.
Saturday
Sunny, with a high near 65.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
2 Miles S Union City CA
 37.56°N 122.01°W (Elev. 115 ft)
Last Update:
12:41 pm PST Dec 7, 2025
Forecast Valid:
1pm PST Dec 7, 2025-6pm PST Dec 13, 2025
 
Forecast Discussion
 
Get as KML Get as XML

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