Coulee Dam Washington Climate Data

Monthly Average Climate Data for Coulee Dam Washington

Switch Data to Celsius/Metric Units
MonthAvg. LowAvg. HighAvg. Precip
January25.5 °F35.6 °F1.1 in.
February27.2 °F42.0 °F0.71 in.
March32.1 °F53.0 °F0.9 in.
April37.8 °F62.9 °F0.85 in.
May45.5 °F72.8 °F1.02 in.
June52.1 °F79.7 °F0.91 in.
July58.8 °F89.9 °F0.46 in.
August58.4 °F89.5 °F0.29 in.
September50.3 °F79.5 °F0.27 in.
October40.7 °F63.4 °F0.71 in.
November32.6 °F46.4 °F1.02 in.
December26.6 °F36.2 °F1.24 in.
Annual40.6 °F62.6 °F9.48 in.

Climate Data for Coulee Dam Washington

Average First Frost DateOct. 21 - Oct. 31
Average Last Frost DateMay 1 - May 10
Average Days With Frost100-125 Days
Plant Hardiness Zone - 2023Zone 7b : 5°F to 10°F
Plant Hardiness Zone - 2012Zone 6b : -5°F to 0°F
Current Drought ConditionsNormal
Köppen Climate ClassificationDsb - Humid Continental Climate - Dry Cool Summer