Port Costa California Climate Data

Monthly Average Climate Data for Port Costa California

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January40.4 °F56.6 °F4.16 in.
February42.0 °F60.8 °F4.01 in.
March44.9 °F65.4 °F2.78 in.
April47.5 °F69.6 °F1.45 in.
May51.4 °F74.1 °F0.63 in.
June54.8 °F79.6 °F0.13 in.
July56.9 °F82.5 °F0.0 in.
August56.6 °F82.3 °F0.03 in.
September55.3 °F81.6 °F0.07 in.
October51.2 °F75.9 °F0.88 in.
November44.2 °F64.8 °F2.01 in.
December40.1 °F56.9 °F4.08 in.
Annual48.8 °F70.8 °F20.23 in.

Climate Data for Port Costa 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 9b : 25°F to 20°F
Current Drought ConditionsNormal
Köppen Climate ClassificationCsb - Warm-Summer Mediterranean Climate
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