National Weather Service Forecast for: Union City CA
Issued by: National Weather Service San Francisco Bay Area/Monterey, CA
Updated: 9:46 am PDT May 4, 2026
 
Today

Today: Partly sunny, with a high near 66. Light west southwest wind becoming west 5 to 10 mph in the afternoon.
Partly Sunny

 Tonight

Tonight: Rain likely, mainly after 3am. Mostly cloudy, with a low around 54. West northwest wind 5 to 10 mph becoming light west after midnight. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.
Slight Chance
Rain then
Rain Likely
 Tuesday

Tuesday: A 10 percent chance of rain before 7am. Cloudy, then gradually becoming mostly sunny, with a high near 64. Calm wind becoming west 5 to 9 mph in the afternoon.
Slight Chance
Rain then
Partly Sunny
 Tuesday
Night
Tuesday Night: Mostly cloudy, with a low around 55. West wind 5 to 9 mph becoming light after midnight.
Mostly Cloudy

 Wednesday

Wednesday: Mostly sunny, with a high near 72. Calm wind becoming west 5 to 8 mph in the afternoon.
Mostly Sunny

 Wednesday
Night
Wednesday Night: Partly cloudy, with a low around 53.
Partly Cloudy

 Thursday

Thursday: Mostly sunny, with a high near 72.
Mostly Sunny

 Thursday
Night
Thursday Night: Partly cloudy, with a low around 52.
Partly Cloudy

 Friday

Friday: Mostly sunny, with a high near 73.
Mostly Sunny
Hi 66 °F Lo 54 °F Hi 64 °F Lo 55 °F Hi 72 °F Lo 53 °F Hi 72 °F Lo 52 °F Hi 73 °F

 

Today
 
 Partly sunny, with a high near 66. Light west southwest wind becoming west 5 to 10 mph in the afternoon.
Tonight
 
 Rain likely, mainly after 3am. Mostly cloudy, with a low around 54. West northwest wind 5 to 10 mph becoming light west after midnight. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.
Tuesday
 
 A 10 percent chance of rain before 7am. Cloudy, then gradually becoming mostly sunny, with a high near 64. Calm wind becoming west 5 to 9 mph in the afternoon.
Tuesday Night
 
 Mostly cloudy, with a low around 55. West wind 5 to 9 mph becoming light after midnight.
Wednesday
 
 Mostly sunny, with a high near 72. Calm wind becoming west 5 to 8 mph in the afternoon.
Wednesday Night
 
 Partly cloudy, with a low around 53.
Thursday
 
 Mostly sunny, with a high near 72.
Thursday Night
 
 Partly cloudy, with a low around 52.
Friday
 
 Mostly sunny, with a high near 73.
Friday Night
 
 Mostly clear, with a low around 53.
Saturday
 
 Sunny, with a high near 82.
Saturday Night
 
 Clear, with a low around 55.
Sunday
 
 Sunny, with a high near 88.

 

Forecast from NOAA-NWS for Union City CA.