National Weather Service Forecast for: 5 Miles SW Portola Valley 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 53. Calm wind.
Patchy Fog

 Thursday

Thursday: Areas of fog before 10am. Otherwise, cloudy, then gradually becoming mostly sunny, with a high near 71. Calm wind becoming west around 6 mph in the afternoon.
Areas Fog
then Partly
Sunny
 Thursday
Night
Thursday Night: Patchy fog between 1am and 3am. Otherwise, mostly cloudy, with a low around 53. Calm wind.
Patchy Fog

 Friday

Friday: Patchy fog before 8am. Otherwise, cloudy, then gradually becoming mostly sunny, with a high near 69. Calm wind becoming west northwest 5 to 7 mph in the afternoon.
Patchy Fog
then Mostly
Sunny
 Friday
Night
Friday Night: Patchy fog after 11pm. Otherwise, mostly cloudy, with a low around 52. West northwest wind around 5 mph becoming calm in the evening.
Patchy Fog

 Saturday

Saturday: Patchy fog before 8am. Otherwise, mostly sunny, with a high near 70.
Patchy Fog
then Sunny
 Saturday
Night
Saturday Night: Patchy fog between 11pm and 4am. Otherwise, partly cloudy, with a low around 52.
Patchy Fog

 Sunday

Sunday: Patchy fog before 9am. Otherwise, partly sunny, with a high near 71.
Patchy Fog
then Mostly
Sunny
 Sunday
Night
Sunday Night: Mostly cloudy, with a low around 53.
Mostly Cloudy
Lo 53 °F Hi 71 °F Lo 53 °F Hi 69 °F Lo 52 °F Hi 70 °F Lo 52 °F Hi 71 °F Lo 53 °F

 

Overnight
 
 Patchy fog. Otherwise, mostly cloudy, with a low around 53. Calm wind.
Thursday
 
 Areas of fog before 10am. Otherwise, cloudy, then gradually becoming mostly sunny, with a high near 71. Calm wind becoming west around 6 mph in the afternoon.
Thursday Night
 
 Patchy fog between 1am and 3am. Otherwise, mostly cloudy, with a low around 53. Calm wind.
Friday
 
 Patchy fog before 8am. Otherwise, cloudy, then gradually becoming mostly sunny, with a high near 69. Calm wind becoming west northwest 5 to 7 mph in the afternoon.
Friday Night
 
 Patchy fog after 11pm. Otherwise, mostly cloudy, with a low around 52. West northwest wind around 5 mph becoming calm in the evening.
Saturday
 
 Patchy fog before 8am. Otherwise, mostly sunny, with a high near 70.
Saturday Night
 
 Patchy fog between 11pm and 4am. Otherwise, partly cloudy, with a low around 52.
Sunday
 
 Patchy fog before 9am. Otherwise, partly sunny, with a high near 71.
Sunday Night
 
 Mostly cloudy, with a low around 53.
Monday
 
 Patchy fog before 9am. Otherwise, partly sunny, with a high near 69.
Monday Night
 
 Areas of fog. Otherwise, mostly cloudy, with a low around 52.
Tuesday
 
 Areas of fog. Otherwise, partly sunny, with a high near 70.
Tuesday Night
 
 Patchy fog. Otherwise, mostly cloudy, with a low around 52.
Wednesday
 
 Partly sunny, with a high near 72.

 

Forecast from NOAA-NWS for 5 Miles SW Portola Valley CA.