Issaquah Washington Climate Data

Monthly Average Climate Data for Issaquah Washington

Switch Data to Fahrenheit
MonthAvg. LowAvg. HighAvg. Precip
January2.3 °C8.5 °C156.72 mm
February2.3 °C10 °C113.28 mm
March3.7 °C12.2 °C127.76 mm
April5.7 °C14.8 °C100.08 mm
May8.7 °C18.6 °C61.98 mm
June11.1 °C20.8 °C54.61 mm
July13.1 °C24.3 °C22.1 mm
August13.2 °C24.6 °C28.7 mm
September10.9 °C21.5 °C48.77 mm
October7.4 °C15.6 °C120.9 mm
November4.3 °C11.1 °C171.96 mm
December2.1 °C8 °C160.53 mm
Annual7.1 °C15.8 °C1167.39 mm

Climate Data for Issaquah Washington

Average First Frost DateOct. 21 - Oct. 31
Average Last Frost DateApr. 21 - Apr. 30
Average Days With Frost50-75 Days
Plant Hardiness Zone - 2023Zone 9a : -6.7°C to -3.9°C
Plant Hardiness Zone - 2012Zone 8b : -9.4°C to -6.7°C
Current Drought ConditionsAbnormally Dry
Köppen Climate ClassificationCsb - Warm-Summer Mediterranean Climate