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, mainly after 3am. Otherwise, increasing clouds, with a low around 45. Calm wind.
Dense Fog


 Thursday

Thursday: A 20 percent chance of rain after 10am. Widespread dense fog, mainly before 10am. Otherwise, mostly cloudy, with a high near 57. Light south wind.
Slight Chance
Rain 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 57. Light south wind becoming south southwest 5 to 9 mph in the morning. Winds could gust as high as 21 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 50. 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 likely, then showers and possibly a thunderstorm after 4pm. Areas of dense fog before 1pm. High near 55. Chance of precipitation is 80%. New rainfall amounts between a half and three quarters of an inch possible.
Showers and
Areas Dense
Fog

 Saturday
Night
Saturday Night: Showers and possibly a thunderstorm before 7pm, then rain between 7pm and 10pm, then showers and possibly a thunderstorm after 10pm. Some of the storms could produce heavy rainfall. Patchy fog after 1am. Low around 51. 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 58.
Heavy Rain


 Sunday
Night
Sunday Night: Rain. Cloudy, with a low around 48.
Rain
Lo 45 °F Hi 57 °F Lo 50 °F Hi 57 °F Lo 50 °F Hi 55 °F Lo 51 °F Hi 58 °F Lo 48 °F

 

Tonight
 
 Widespread dense fog, mainly after 3am. Otherwise, increasing clouds, with a low around 45. Calm wind.
Thursday
 
 A 20 percent chance of rain after 10am. Widespread dense fog, mainly before 10am. Otherwise, mostly cloudy, with a high near 57. Light south wind.
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 57. Light south wind becoming south southwest 5 to 9 mph in the morning. Winds could gust as high as 21 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 50. Light west wind. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.
Saturday
 
 Rain likely, then showers and possibly a thunderstorm after 4pm. Areas of dense fog before 1pm. High near 55. Chance of precipitation is 80%. New rainfall amounts between a half and three quarters of an inch possible.
Saturday Night
 
 Showers and possibly a thunderstorm before 7pm, then rain between 7pm and 10pm, then showers and possibly a thunderstorm after 10pm. Some of the storms could produce heavy rainfall. Patchy fog after 1am. Low around 51. Chance of precipitation is 90%.
Sunday
 
 Showers and possibly a thunderstorm. Some of the storms could produce heavy rainfall. Cloudy, with a high near 58.
Sunday Night
 
 Rain. Cloudy, with a low around 48.
Monday
 
 Rain likely. Mostly cloudy, with a high near 56.
Monday Night
 
 Rain likely. Patchy fog. Otherwise, mostly cloudy, with a low around 45.
Tuesday
 
 Rain likely. Patchy fog. Otherwise, mostly cloudy, with a high near 53.
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.