National Weather Service Forecast for: Petaluma CA
Issued by: National Weather Service San Francisco Bay Area/Monterey, CA
Updated: 12:46 am PDT Aug 20, 2026
 
Overnight

Overnight: Patchy fog. Otherwise, mostly cloudy, with a low around 54. Calm wind.
Patchy Fog

 Thursday

Thursday: Patchy fog before 10am. Otherwise, mostly cloudy, with a high near 80. Calm wind becoming west 5 to 9 mph in the afternoon. Winds could gust as high as 18 mph.
Patchy Fog
then Partly
Sunny
 Thursday
Night
Thursday Night: Mostly cloudy, with a low around 55. West wind 5 to 7 mph becoming calm after midnight.
Mostly Cloudy

 Friday

Friday: Mostly cloudy, then gradually becoming sunny, with a high near 78. Light west wind increasing to 5 to 10 mph in the morning. Winds could gust as high as 21 mph.
Decreasing
Clouds
 Friday
Night
Friday Night: Partly cloudy, with a low around 53. West wind 5 to 10 mph, with gusts as high as 21 mph.
Partly Cloudy

 Saturday

Saturday: Sunny, with a high near 81.
Sunny

 Saturday
Night
Saturday Night: Patchy fog after 2am. Otherwise, partly cloudy, with a low around 54.
Mostly Clear
then Patchy
Fog
 Sunday

Sunday: Areas of fog before 9am. Otherwise, mostly sunny, with a high near 83.
Areas Fog
then Sunny
 Sunday
Night
Sunday Night: Patchy fog after 2am. Otherwise, mostly cloudy, with a low around 54.
Partly Cloudy
then Patchy
Fog
Lo 54 °F Hi 80 °F Lo 55 °F Hi 78 °F Lo 53 °F Hi 81 °F Lo 54 °F Hi 83 °F Lo 54 °F

 

Overnight
 
 Patchy fog. Otherwise, mostly cloudy, with a low around 54. Calm wind.
Thursday
 
 Patchy fog before 10am. Otherwise, mostly cloudy, with a high near 80. Calm wind becoming west 5 to 9 mph in the afternoon. Winds could gust as high as 18 mph.
Thursday Night
 
 Mostly cloudy, with a low around 55. West wind 5 to 7 mph becoming calm after midnight.
Friday
 
 Mostly cloudy, then gradually becoming sunny, with a high near 78. Light west wind increasing to 5 to 10 mph in the morning. Winds could gust as high as 21 mph.
Friday Night
 
 Partly cloudy, with a low around 53. West wind 5 to 10 mph, with gusts as high as 21 mph.
Saturday
 
 Sunny, with a high near 81.
Saturday Night
 
 Patchy fog after 2am. Otherwise, partly cloudy, with a low around 54.
Sunday
 
 Areas of fog before 9am. Otherwise, mostly sunny, with a high near 83.
Sunday Night
 
 Patchy fog after 2am. Otherwise, mostly cloudy, with a low around 54.
Monday
 
 Patchy fog before 10am. Otherwise, partly sunny, with a high near 78.
Monday Night
 
 Patchy fog. Otherwise, mostly cloudy, with a low around 53.
Tuesday
 
 Patchy fog. Otherwise, partly sunny, with a high near 80.
Tuesday Night
 
 Patchy fog. Otherwise, partly cloudy, with a low around 53.
Wednesday
 
 Areas of fog. Otherwise, partly sunny, with a high near 82.

 

Forecast from NOAA-NWS for Petaluma CA.