NWS Forecast for Saint Helena CA

National Weather Service Forecast for: Saint Helena CA
Issued by: National Weather Service San Francisco Bay Area/Monterey, CA

Updated: 1:40 am PST Dec 5, 2025

Overnight Mostly Clear	Friday Sunny	Friday Night Mostly Clear	Saturday Areas Fog then Sunny	Saturday Night Partly Cloudy	Sunday Patchy Fog then Mostly Sunny	Sunday Night Partly Cloudy	Monday Areas Fog then Sunny	Monday Night Patchy Fog
Lo 38 °F	Hi 63 °F	Lo 42 °F	Hi 64 °F	Lo 43 °F	Hi 65 °F	Lo 43 °F	Hi 66 °F	Lo 45 °F

Coastal Flood Advisory
Cold Weather Advisory

Overnight	Mostly clear, with a low around 38. Northeast wind around 5 mph.
Friday	Sunny, with a high near 63. North northeast wind around 6 mph becoming calm.
Friday Night	Mostly clear, with a low around 42. North northeast wind 3 to 7 mph.
Saturday	Areas of fog between 9am and 11am. Otherwise, sunny, with a high near 64. Calm wind becoming west northwest 5 to 7 mph in the afternoon.
Saturday Night	Partly cloudy, with a low around 43. North wind 5 to 7 mph.
Sunday	Patchy fog before 10am. Otherwise, mostly sunny, with a high near 65.
Sunday Night	Partly cloudy, with a low around 43.
Monday	Areas of fog before 11am. Otherwise, sunny, with a high near 66.
Monday Night	Patchy fog after 9pm. Otherwise, partly cloudy, with a low around 45.
Tuesday	Patchy fog before 10am. Otherwise, mostly sunny, with a high near 67.
Tuesday Night	Patchy fog. Otherwise, partly cloudy, with a low around 46.
Wednesday	Patchy fog. Otherwise, mostly sunny, with a high near 68.
Wednesday Night	Patchy fog. Otherwise, mostly clear, with a low around 46.
Thursday	Areas of fog. Otherwise, sunny, with a high near 69.

Forecast from NOAA-NWS for Saint Helena CA.