Sumas Washington Climate Data

Monthly Average Climate Data for Sumas Washington

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January33.0 °F44.0 °F6.71 in.
February34.1 °F47.6 °F4.02 in.
March36.5 °F52.4 °F5.32 in.
April40.3 °F58.8 °F4.04 in.
May45.9 °F65.8 °F3.43 in.
June50.5 °F70.2 °F2.5 in.
July52.9 °F76.0 °F1.57 in.
August52.4 °F77.0 °F1.56 in.
September48.3 °F71.0 °F2.93 in.
October42.9 °F59.7 °F5.58 in.
November37.3 °F49.5 °F7.17 in.
December33.0 °F43.3 °F6.31 in.
Annual42.3 °F59.6 °F51.14 in.

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 : 15°F to 20°F
Plant Hardiness Zone - 2012Zone 8a : 10°F to 15°F
Current Drought ConditionsAbnormally Dry
Köppen Climate ClassificationCfb - Temperate Oceanic Climate