National Weather Service Forecast for: Bethel Island CA
Issued by: National Weather Service San Francisco Bay Area/Monterey, CA
Updated: 1:40 am PST Dec 5, 2025
 
Overnight

Overnight: Areas of fog. Areas of frost. Otherwise, mostly cloudy, with a low around 35. Light east southeast wind.
Areas Frost
and Areas Fog
 Friday

Friday: Widespread dense fog before 9am. Otherwise, mostly cloudy, then gradually becoming sunny, with a high near 53. Southeast wind around 5 mph becoming calm in the morning.
Dense Fog
then Mostly
Sunny
 Friday
Night
Friday Night: Partly cloudy, with a low around 41. South southeast wind 5 to 7 mph becoming light and variable after midnight.
Partly Cloudy

 Saturday

Saturday: Mostly cloudy, then gradually becoming sunny, with a high near 57. North northwest wind 3 to 6 mph.
Decreasing
Clouds
 Saturday
Night
Saturday Night: Partly cloudy, with a low around 44. Northwest wind 3 to 7 mph.
Partly Cloudy

 Sunday

Sunday: Patchy fog before 10am. Otherwise, partly sunny, with a high near 59.
Patchy Fog
then Partly
Sunny
 Sunday
Night
Sunday Night: Patchy fog before 10pm. Otherwise, partly cloudy, with a low around 44.
Patchy Fog
then Partly
Cloudy
 Monday

Monday: Mostly sunny, with a high near 59.
Mostly Sunny

 Monday
Night
Monday Night: Patchy fog after 9pm. Otherwise, partly cloudy, with a low around 44.
Patchy Fog
Lo 35 °F Hi 53 °F Lo 41 °F Hi 57 °F Lo 44 °F Hi 59 °F Lo 44 °F Hi 59 °F Lo 44 °F

Cold Weather Advisory
 

Overnight
 
 Areas of fog. Areas of frost. Otherwise, mostly cloudy, with a low around 35. Light east southeast wind.
Friday
 
 Widespread dense fog before 9am. Otherwise, mostly cloudy, then gradually becoming sunny, with a high near 53. Southeast wind around 5 mph becoming calm in the morning.
Friday Night
 
 Partly cloudy, with a low around 41. South southeast wind 5 to 7 mph becoming light and variable after midnight.
Saturday
 
 Mostly cloudy, then gradually becoming sunny, with a high near 57. North northwest wind 3 to 6 mph.
Saturday Night
 
 Partly cloudy, with a low around 44. Northwest wind 3 to 7 mph.
Sunday
 
 Patchy fog before 10am. Otherwise, partly sunny, with a high near 59.
Sunday Night
 
 Patchy fog before 10pm. Otherwise, partly cloudy, with a low around 44.
Monday
 
 Mostly sunny, with a high near 59.
Monday Night
 
 Patchy fog after 9pm. Otherwise, partly cloudy, with a low around 44.
Tuesday
 
 Patchy fog before 10am. Otherwise, partly sunny, with a high near 60.
Tuesday Night
 
 Patchy fog. Otherwise, mostly cloudy, with a low around 46.
Wednesday
 
 Patchy fog. Otherwise, partly sunny, with a high near 61.
Wednesday Night
 
 Patchy fog. Otherwise, partly cloudy, with a low around 46.
Thursday
 
 Patchy fog. Otherwise, mostly sunny, with a high near 61.

 

Forecast from NOAA-NWS for Bethel Island CA.