Portola Valley California Climate Data

Monthly Average Climate Data for Portola Valley California

Switch Data to Fahrenheit
MonthAvg. LowAvg. HighAvg. Precip
January5.3 °C15.7 °C142.75 mm
February5.8 °C16.8 °C135.64 mm
March6.4 °C18.6 °C111.76 mm
April7 °C20.6 °C52.58 mm
May8.8 °C23.7 °C17.78 mm
June10.4 °C27.3 °C6.1 mm
July11.8 °C28.9 °C0.25 mm
August11.9 °C28.4 °C1.02 mm
September11.6 °C28.2 °C2.54 mm
October9.9 °C25.1 °C29.97 mm
November7 °C19.3 °C65.79 mm
December5 °C15.3 °C151.89 mm
Annual8.4 °C22.3 °C718.07 mm

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 : -3.9°C to -1.1°C
Plant Hardiness Zone - 2012Zone 9b : -3.9°C to -1.1°C
Current Drought ConditionsNormal
Köppen Climate ClassificationCsb - Warm-Summer Mediterranean Climate
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