Portola Valley California Climate Data

Monthly Average Climate Data for Portola Valley California

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January41.5 °F60.2 °F5.62 in.
February42.4 °F62.3 °F5.34 in.
March43.5 °F65.5 °F4.4 in.
April44.6 °F69.0 °F2.07 in.
May47.9 °F74.7 °F0.7 in.
June50.7 °F81.1 °F0.24 in.
July53.3 °F84.1 °F0.01 in.
August53.5 °F83.1 °F0.04 in.
September52.9 °F82.7 °F0.1 in.
October49.9 °F77.2 °F1.18 in.
November44.6 °F66.7 °F2.59 in.
December41.0 °F59.5 °F5.98 in.
Annual47.2 °F72.2 °F28.27 in.

Climate Data for Portola Valley California

Average First Frost DateDec. 21 - Dec. 31
Average Last Frost DateFeb. 21 - Feb. 29
Average Days With Frost5-10 Days
Plant Hardiness Zone - 2023Zone 9b : 25°F to 20°F
Plant Hardiness Zone - 2012Zone 9b : 25°F to 20°F
Current Drought ConditionsNormal
Köppen Climate ClassificationCsb - Warm-Summer Mediterranean Climate
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