Castro Valley California Climate Data

Monthly Average Climate Data for Castro Valley California

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January41.8 °F58.1 °F3.94 in.
February43.6 °F61.0 °F3.91 in.
March45.2 °F63.8 °F3.0 in.
April47.1 °F66.3 °F1.59 in.
May50.7 °F69.2 °F0.73 in.
June53.5 °F73.6 °F0.21 in.
July56.0 °F75.8 °F0.01 in.
August56.5 °F76.2 °F0.04 in.
September55.6 °F76.7 °F0.11 in.
October52.0 °F73.1 °F0.91 in.
November45.5 °F64.6 °F2.11 in.
December41.6 °F58.0 °F3.99 in.
Annual49.1 °F68 °F20.55 in.

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 : 25°F to 20°F
Plant Hardiness Zone - 2012Zone 10a : 30°F to 25°F
Current Drought ConditionsNormal
Köppen Climate ClassificationCsb - Warm-Summer Mediterranean Climate