| 2023 Hardiness Zone: | Zone 6b: -5°F to 0°F Zone 7b: 5°F to 10°F Zone 7a: 0°F to 5°F |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 6b: -5°F to 0°F Zone 7a: 0°F to 5°F |
| 1990 Hardiness Zone: | Zone 6a: -10F to -5F |
| Average First Frost Date: | Oct. 1 - Oct. 10 |
| Average Last Frost Date: | May 1 - May 10 |
| Koppen-Geiger Climate Zone: | BSk - Cold Semi-Arid Climate |
| Ecoregion: | 10e - Pleistocene Lake Basins |
| Heat Zone Days: | 1 - 7 days Over 86°F |
Annual Climate Data for ZIP Code 98926 - Ellensburg, WA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 20 | 24 | 29 | 34 | 42 | 48 | 53 | 52 | 43 | 33 | 27 | 20 | 35 |
| Avg Max Temp (°F) | 34 | 41 | 51 | 59 | 67 | 74 | 82 | 82 | 74 | 61 | 44 | 34 | 58 |
| Avg Precip (In.) | 1.72 | 1.09 | .83 | .61 | .63 | .69 | .37 | .37 | .5 | .6 | 1.52 | 1.63 | 10.56 |