TODAY JUN07
TEMPERATURE53
HUMIDITY74
PRESSURE
WIND COND.319 3
  • 6948Sun
  • 7849Mon
  • 8356Tue
  • 8355Wed
  • 7854Thu
daynightWeather update from LOS ALTOS at
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Portola Valley Average Temperature

In the event that the weather data was unavailable for this city, estimates based upon nearby cities were used.
MonthTemp. (min)Temp. (max)Temp. (avg)Precipitation
January42°F61°F50°F2.4"
February45°F63°F53°F2.4"
March47°F67°F56°F2.0"
April49°F70°F58°F1.3"
May53°F73°F61°F0.3"
June56°F77°F65°F0.2"
July59°F78°F67°F0.0"
August59°F78°F66°F0.0"
September57°F80°F67°F0.1"
October53°F75°F63°F0.7"
November47°F67°F56°F1.3"
December42°F60°F51°F2.6"

Did you know?

  • The highest monthly average temperature in Portola Valley for July is 67 degrees.
  • The lowest monthly average temperature in Portola Valley for January is 50 degrees.
  • The most monthly precipitation in Portola Valley occurs in December with 2.6 inches.
  • The air quality index in Portola Valley is 3% better than the national average.
  • The pollution index in Portola Valley is 127% worse than the national average.

Compare Portola Valley, CA Weather To Other Cities

      vs

      Portola Valley air quality index & pollution index

      In the event that the air quality/pollution data was unavailable for this city, estimates based upon nearby cities were used.
      IndexPortola ValleyCaliforniaNational
      Air quality index485550
      Pollution index11,477,20018,106,7265,066,862

      Portola Valley air quality information

      MeasurementTotal
      Days measured365
      Days with good air quality204
      Days with moderate air quality153
      Days w/ poor A.Q. for sensitive groups7
      Days with unhealthy air quality1

      Portola Valley air quality information

      PollutantTotal
      Arsenic0.070%
      Benzene0.110%
      Carbon Tetrachloride0.000%
      Lead0.160%
      Mercury0.090%

      Average monthly Portola Valley temperature with heat index

      Portola Valley monthly precipitation with daily maximum

      Portola Valley monthly snow depth with daily maximum

      Portola Valley monthly wind speed information

      Nearby cities with good air quality

      City, StatePopulationAir Quality IndexNational Avg.
      Pescadero, CA1,0403628%
      Lexington Hills, CA2,6173628%
      Loma Mar, CA1503628%
      Fremont, CA227,934484%
      Ladera, CA1,514484%
      Portola Valley, CA4,550484%

      Cities with similar population

      City, StatePopulationAir Quality IndexNational Avg.
      Niskayuna, NY4,5483628%
      Mullins, SC4,5534020%
      Gibraltar, MI4,547688%
      Madisonville, TX4,5464020%
      Cobleskill, NY4,5543628%
      Portola Valley, CA4,550484%
      Source: The Portola Valley, CA weather data displayed above is derived from the NOAA (National Oceanic and Atmospheric). Air quality and pollution data is derived from the EPA (United States Environmental Protection Agency). Air quality and pollution levels measured in a particular area may not be representative of the entire county.