| 2023 Hardiness Zone: | Zone 6b: -5°F to 0°F |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 6b: -5°F to 0°F |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F |
| Average First Frost Date: | Sep. 21 - Sep. 30 |
| Average Last Frost Date: | May 11 - May 20 |
| Koppen-Geiger Climate Zone: | Dsb - Humid Continental Climate - Dry Cool Summer |
| Ecoregion: | 10h - Palouse Hills |
| Heat Zone Days: | 1 - 7 days Over 86°F |
Annual Climate Data for ZIP Code 99161 - Palouse, WA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 25 | 29 | 33 | 36 | 41 | 45 | 49 | 49 | 41 | 35 | 29 | 25 | 36 |
| Avg Max Temp (°F) | 37 | 44 | 54 | 58 | 67 | 73 | 82 | 84 | 76 | 60 | 43 | 37 | 59 |
| Avg Precip (In.) | 2.75 | 2.39 | 2.32 | 2.03 | 2.24 | 1.67 | 1.03 | .99 | 1.1 | 1.68 | 3.09 | 3.09 | 24.37 |