Zip code 99114, Colville WA is in USDA Hardiness Zone 5a: -20F to -15F. Using updated climate data through 2010, 99114 is in the Plantmaps Hardiness Zone 4b: -25F to -20F. The average first frost in 99114 is between September 21 - 30, while the average last frost occurs between May 11 - 20. 99114 is part of Ecoregion 15r - Okanogan-Colville Xeric Valleys and Foothills. 99114 averages 31 - 45 days per year where the temperatue exceeds 86°F. The average annual high temperature in 99114 is 58°F and the average annual low temperature is 35°F.