National Weather Service Forecast for: Union City CA
Issued by: National Weather Service San Francisco Bay Area/Monterey, CA
Updated: 8:57 am PDT Oct 6, 2026
 
Today

Today: Sunny, with a high near 90. Calm wind becoming west northwest 5 to 9 mph in the afternoon.
Sunny
 Tonight

Tonight: Clear, with a low around 63. Calm wind.
Clear
 Wednesday

Wednesday: Sunny, with a high near 88. Calm wind becoming west northwest 5 to 8 mph in the afternoon.
Sunny
 Wednesday
Night
Wednesday Night: Mostly clear, with a low around 60. West northwest wind 5 to 8 mph becoming calm in the evening.
Mostly Clear
 Thursday

Thursday: Sunny, with a high near 86. Calm wind becoming west northwest around 6 mph in the afternoon.
Sunny
 Thursday
Night
Thursday Night: Mostly clear, with a low around 61.
Mostly Clear
 Friday

Friday: Sunny, with a high near 80.
Sunny
 Friday
Night
Friday Night: Mostly clear, with a low around 59.
Mostly Clear
 Saturday

Saturday: Mostly sunny, with a high near 73.
Mostly Sunny
Hi 90 °F Lo 63 °F Hi 88 °F Lo 60 °F Hi 86 °F Lo 61 °F Hi 80 °F Lo 59 °F Hi 73 °F

Heat Advisory
 

Today
 
 Sunny, with a high near 90. Calm wind becoming west northwest 5 to 9 mph in the afternoon.
Tonight
 
 Clear, with a low around 63. Calm wind.
Wednesday
 
 Sunny, with a high near 88. Calm wind becoming west northwest 5 to 8 mph in the afternoon.
Wednesday Night
 
 Mostly clear, with a low around 60. West northwest wind 5 to 8 mph becoming calm in the evening.
Thursday
 
 Sunny, with a high near 86. Calm wind becoming west northwest around 6 mph in the afternoon.
Thursday Night
 
 Mostly clear, with a low around 61.
Friday
 
 Sunny, with a high near 80.
Friday Night
 
 Mostly clear, with a low around 59.
Saturday
 
 Mostly sunny, with a high near 73.
Saturday Night
 
 Partly cloudy, with a low around 56.
Sunday
 
 Sunny, with a high near 71.
Sunday Night
 
 Mostly clear, with a low around 54.
Columbus Day
 
 Sunny, with a high near 74.

 

Forecast from NOAA-NWS for Union City CA.