National Weather Service Forecast for: Guerneville CA
Issued by: National Weather Service San Francisco Bay Area/Monterey, CA
Updated: 1:24 pm PST Dec 17, 2025
 
Tonight

Tonight: Widespread dense fog. Otherwise, increasing clouds, with a low around 45. Calm wind.
Dense Fog


 Thursday

Thursday: Rain likely, mainly after 4pm. Widespread dense fog before 2pm, then patchy dense fog after 4pm. Otherwise, mostly cloudy, with a high near 56. Calm wind. Chance of precipitation is 60%.
Rain Likely
and Dense Fog

 Thursday
Night
Thursday Night: Rain. Areas of fog. Low around 50. Calm wind. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.
Rain and
Areas Fog

 Friday

Friday: Rain. High near 56. South wind 3 to 8 mph. Winds could gust as high as 20 mph. Chance of precipitation is 100%. New precipitation amounts between a half and three quarters of an inch possible.
Rain


 Friday
Night
Friday Night: Rain, mainly before 10pm. Patchy fog after 10pm. Low around 49. Light west wind. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.
Rain and
Patchy Fog
then Chance
Rain and
Patchy Fog
 Saturday

Saturday: Rain, mainly after 10am. Areas of dense fog before 1pm. High near 54. Chance of precipitation is 80%. New precipitation amounts between a half and three quarters of an inch possible.
Rain and
Areas Dense
Fog

 Saturday
Night
Saturday Night: Rain before 10pm, then showers and possibly a thunderstorm after 10pm. Some of the storms could produce heavy rainfall. Patchy fog before 10pm, then patchy fog after 1am. Low around 50. Chance of precipitation is 90%.
Heavy Rain
and Patchy
Fog

 Sunday

Sunday: Showers and possibly a thunderstorm. Some of the storms could produce heavy rainfall. Cloudy, with a high near 56.
Heavy Rain


 Sunday
Night
Sunday Night: Rain. Cloudy, with a low around 48.
Rain
Lo 45 °F Hi 56 °F Lo 50 °F Hi 56 °F Lo 49 °F Hi 54 °F Lo 50 °F Hi 56 °F Lo 48 °F

 

Tonight
 
 Widespread dense fog. Otherwise, increasing clouds, with a low around 45. Calm wind.
Thursday
 
 Rain likely, mainly after 4pm. Widespread dense fog before 2pm, then patchy dense fog after 4pm. Otherwise, mostly cloudy, with a high near 56. Calm wind. Chance of precipitation is 60%.
Thursday Night
 
 Rain. Areas of fog. Low around 50. Calm wind. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch possible.
Friday
 
 Rain. High near 56. South wind 3 to 8 mph. Winds could gust as high as 20 mph. Chance of precipitation is 100%. New precipitation amounts between a half and three quarters of an inch possible.
Friday Night
 
 Rain, mainly before 10pm. Patchy fog after 10pm. Low around 49. Light west wind. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.
Saturday
 
 Rain, mainly after 10am. Areas of dense fog before 1pm. High near 54. Chance of precipitation is 80%. New precipitation amounts between a half and three quarters of an inch possible.
Saturday Night
 
 Rain before 10pm, then showers and possibly a thunderstorm after 10pm. Some of the storms could produce heavy rainfall. Patchy fog before 10pm, then patchy fog after 1am. Low around 50. Chance of precipitation is 90%.
Sunday
 
 Showers and possibly a thunderstorm. Some of the storms could produce heavy rainfall. Cloudy, with a high near 56.
Sunday Night
 
 Rain. Cloudy, with a low around 48.
Monday
 
 Rain likely. Mostly cloudy, with a high near 55.
Monday Night
 
 Rain likely. Patchy fog. Otherwise, mostly cloudy, with a low around 44.
Tuesday
 
 Rain likely. Patchy fog. Otherwise, mostly cloudy, with a high near 52.
Tuesday Night
 
 Rain. Cloudy, with a low around 46.
Wednesday
 
 Rain likely. Mostly cloudy, with a high near 54.

 

Forecast from NOAA-NWS for Guerneville CA.