Castro Valley California Climate Data

Monthly Average Climate Data for Castro Valley California

Switch Data to Fahrenheit
MonthAvg. LowAvg. HighAvg. Precip
January5.4 °C14.5 °C100.08 mm
February6.4 °C16.1 °C99.31 mm
March7.3 °C17.7 °C76.2 mm
April8.4 °C19.1 °C40.39 mm
May10.4 °C20.7 °C18.54 mm
June11.9 °C23.1 °C5.33 mm
July13.3 °C24.3 °C0.25 mm
August13.6 °C24.6 °C1.02 mm
September13.1 °C24.8 °C2.79 mm
October11.1 °C22.8 °C23.11 mm
November7.5 °C18.1 °C53.59 mm
December5.3 °C14.4 °C101.35 mm
Annual9.5 °C20 °C521.96 mm

Climate Data for Castro Valley California

Average First Frost DateJan. 1 - Jan. 10
Average Last Frost DateJan. 21 - Jan. 31
Average Days With FrostFrost Rare
Plant Hardiness Zone - 2023Zone 9b : -3.9°C to -1.1°C
Plant Hardiness Zone - 2012Zone 10a : -1.1°C to 1.7°C
Current Drought ConditionsNormal
Köppen Climate ClassificationCsb - Warm-Summer Mediterranean Climate
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