Sumas Washington Climate Data

Monthly Average Climate Data for Sumas Washington

Switch Data to Fahrenheit
MonthAvg. LowAvg. HighAvg. Precip
January0.6 °C6.7 °C170.43 mm
February1.2 °C8.7 °C102.11 mm
March2.5 °C11.3 °C135.13 mm
April4.6 °C14.9 °C102.62 mm
May7.7 °C18.8 °C87.12 mm
June10.3 °C21.2 °C63.5 mm
July11.6 °C24.4 °C39.88 mm
August11.3 °C25 °C39.62 mm
September9.1 °C21.7 °C74.42 mm
October6.1 °C15.4 °C141.73 mm
November2.9 °C9.7 °C182.12 mm
December0.6 °C6.3 °C160.27 mm
Annual5.7 °C15.3 °C1298.95 mm

Climate Data for Sumas Washington

Average First Frost DateOct. 21 - Oct. 31
Average Last Frost DateApr. 21 - Apr. 30
Average Days With Frost40-50 Days
Plant Hardiness Zone - 2023Zone 8b : -9.4°C to -6.7°C
Plant Hardiness Zone - 2012Zone 8a : -12.2°C to -9.4°C
Current Drought ConditionsAbnormally Dry
Köppen Climate ClassificationCfb - Temperate Oceanic Climate
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