National Weather Service Forecast for: Union City CA
Issued by: National Weather Service San Francisco Bay Area/Monterey, CA
Updated: 11:44 pm PST Feb 1, 2026
 
Tonight

Tonight: Mostly clear, with a low around 44. Light northeast wind.
Mostly Clear
 Monday

Monday: Sunny, with a high near 67. Calm wind becoming west northwest 5 to 7 mph in the afternoon.
Sunny
 Monday
Night
Monday Night: Mostly clear, with a low around 43. Calm wind.
Mostly Clear
 Tuesday

Tuesday: Sunny, with a high near 69. Calm wind becoming north northeast around 5 mph in the afternoon.
Sunny
 Tuesday
Night
Tuesday Night: Mostly clear, with a low around 44. Calm wind.
Mostly Clear
 Wednesday

Wednesday: Sunny, with a high near 70.
Sunny
 Wednesday
Night
Wednesday Night: Mostly clear, with a low around 45.
Mostly Clear
 Thursday

Thursday: Sunny, with a high near 70.
Sunny
 Thursday
Night
Thursday Night: Mostly cloudy, with a low around 48.
Mostly Cloudy
Lo 44 °F Hi 67 °F Lo 43 °F Hi 69 °F Lo 44 °F Hi 70 °F Lo 45 °F Hi 70 °F Lo 48 °F

 

Tonight
 
 Mostly clear, with a low around 44. Light northeast wind.
Monday
 
 Sunny, with a high near 67. Calm wind becoming west northwest 5 to 7 mph in the afternoon.
Monday Night
 
 Mostly clear, with a low around 43. Calm wind.
Tuesday
 
 Sunny, with a high near 69. Calm wind becoming north northeast around 5 mph in the afternoon.
Tuesday Night
 
 Mostly clear, with a low around 44. Calm wind.
Wednesday
 
 Sunny, with a high near 70.
Wednesday Night
 
 Mostly clear, with a low around 45.
Thursday
 
 Sunny, with a high near 70.
Thursday Night
 
 Mostly cloudy, with a low around 48.
Friday
 
 Mostly sunny, with a high near 67.
Friday Night
 
 Mostly cloudy, with a low around 48.
Saturday
 
 Mostly sunny, with a high near 67.
Saturday Night
 
 Partly cloudy, with a low around 48.
Sunday
 
 A slight chance of rain. Mostly sunny, with a high near 67.

 

Forecast from NOAA-NWS for Union City CA.