National Weather Service Forecast for: Union City CA
Issued by: National Weather Service San Francisco Bay Area/Monterey, CA
Updated: 5:12 am PDT Mar 19, 2026
 
Today

Today: Sunny, with a high near 92. Calm wind becoming west northwest around 6 mph in the afternoon.
Sunny
 Tonight

Tonight: Clear, with a low around 61. Light and variable wind.
Clear
 Friday

Friday: Sunny, with a high near 91. Calm wind becoming west northwest around 5 mph in the afternoon.
Sunny
 Friday
Night
Friday Night: Increasing clouds, with a low around 59. West northwest wind around 6 mph becoming calm in the evening.
Increasing
Clouds
 Saturday

Saturday: Partly sunny, with a high near 81. Calm wind becoming west 5 to 8 mph in the afternoon.
Partly Sunny
 Saturday
Night
Saturday Night: Mostly clear, with a low around 53.
Mostly Clear
 Sunday

Sunday: Sunny, with a high near 78.
Sunny
 Sunday
Night
Sunday Night: Mostly clear, with a low around 51.
Mostly Clear
 Monday

Monday: Sunny, with a high near 81.
Sunny
Hi 92 °F Lo 61 °F Hi 91 °F Lo 59 °F Hi 81 °F Lo 53 °F Hi 78 °F Lo 51 °F Hi 81 °F

Heat Advisory
 

Today
 
 Sunny, with a high near 92. Calm wind becoming west northwest around 6 mph in the afternoon.
Tonight
 
 Clear, with a low around 61. Light and variable wind.
Friday
 
 Sunny, with a high near 91. Calm wind becoming west northwest around 5 mph in the afternoon.
Friday Night
 
 Increasing clouds, with a low around 59. West northwest wind around 6 mph becoming calm in the evening.
Saturday
 
 Partly sunny, with a high near 81. Calm wind becoming west 5 to 8 mph in the afternoon.
Saturday Night
 
 Mostly clear, with a low around 53.
Sunday
 
 Sunny, with a high near 78.
Sunday Night
 
 Mostly clear, with a low around 51.
Monday
 
 Sunny, with a high near 81.
Monday Night
 
 Mostly clear, with a low around 54.
Tuesday
 
 Sunny, with a high near 81.
Tuesday Night
 
 Mostly clear, with a low around 52.
Wednesday
 
 Sunny, with a high near 74.

 

Forecast from NOAA-NWS for Union City CA.