National Weather Service Forecast for: Saint Helena 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, mostly cloudy, with a low around 43. Calm wind.
Dense Fog

 Thursday

Thursday: A 30 percent chance of rain after 4pm. Widespread fog before 2pm, then patchy fog after 5pm. Otherwise, mostly cloudy, with a high near 59. Calm wind.
Fog then
Chance Rain
and Areas Fog
 Thursday
Night
Thursday Night: Rain likely, mainly after 10pm. Widespread fog, mainly after 7pm. Otherwise, cloudy, with a low around 48. Calm wind. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.
Rain Likely
and Fog

 Friday

Friday: Rain. Patchy fog before 10am. High near 56. Calm wind becoming south southwest around 6 mph in the morning. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.
Rain and
Patchy Fog

 Friday
Night
Friday Night: Rain, mainly before 10pm. Widespread fog, mainly after 1am. Low around 49. Light southwest wind. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.
Rain and
Patchy Fog
then Chance
Rain and Fog
 Saturday

Saturday: Rain likely, mainly after 10am. Widespread fog, mainly before 10am. Otherwise, mostly cloudy, with a high near 55. Chance of precipitation is 60%. New precipitation amounts between a quarter and half of an inch possible.
Rain Likely
and Fog

 Saturday
Night
Saturday Night: Rain. Patchy fog. Low around 50. Chance of precipitation is 90%.
Rain and
Patchy Fog

 Sunday

Sunday: Rain. Cloudy, with a high near 57.
Rain

 Sunday
Night
Sunday Night: Rain. Cloudy, with a low around 48.
Rain
Lo 43 °F Hi 59 °F Lo 48 °F Hi 56 °F Lo 49 °F Hi 55 °F Lo 50 °F Hi 57 °F Lo 48 °F

 

Tonight
 
 Widespread dense fog. Otherwise, mostly cloudy, with a low around 43. Calm wind.
Thursday
 
 A 30 percent chance of rain after 4pm. Widespread fog before 2pm, then patchy fog after 5pm. Otherwise, mostly cloudy, with a high near 59. Calm wind.
Thursday Night
 
 Rain likely, mainly after 10pm. Widespread fog, mainly after 7pm. Otherwise, cloudy, with a low around 48. Calm wind. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.
Friday
 
 Rain. Patchy fog before 10am. High near 56. Calm wind becoming south southwest around 6 mph in the morning. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.
Friday Night
 
 Rain, mainly before 10pm. Widespread fog, mainly after 1am. Low around 49. Light southwest wind. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.
Saturday
 
 Rain likely, mainly after 10am. Widespread fog, mainly before 10am. Otherwise, mostly cloudy, with a high near 55. Chance of precipitation is 60%. New precipitation amounts between a quarter and half of an inch possible.
Saturday Night
 
 Rain. Patchy fog. Low around 50. Chance of precipitation is 90%.
Sunday
 
 Rain. Cloudy, with a high near 57.
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, cloudy, with a low around 44.
Tuesday
 
 Rain likely. Areas of fog. Otherwise, mostly cloudy, with a high near 52.
Tuesday Night
 
 Rain. Patchy fog. Otherwise, cloudy, with a low around 44.
Wednesday
 
 Rain likely. Patchy fog. Otherwise, mostly cloudy, with a high near 53.

 

Forecast from NOAA-NWS for Saint Helena CA.