| 2023 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 4b: -25°F to -20°F Zone 5b: -15°F to -10°F |
| 2012 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 4b: -25°F to -20°F Zone 4a: -30°F to -25°F |
| 1990 Hardiness Zone: | Zone 4a: -30F to -25F |
| Average First Frost Date: | Sep. 21 - Sep. 30 |
| Average Last Frost Date: | May 11 - May 20 |
| Koppen-Geiger Climate Zone: | BSk - Cold Semi-Arid Climate |
| Ecoregion: | 18g - Bighorn Salt Desert Shrub Basin |
| Heat Zone Days: | 61 - 90 days Over 86°F |
Annual Climate Data for ZIP Code 82426 - Greybull, WY | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 2 | 10 | 23 | 32 | 42 | 50 | 56 | 53 | 42 | 31 | 17 | 6 | 30 |
| Avg Max Temp (°F) | 27 | 38 | 51 | 61 | 71 | 82 | 89 | 88 | 76 | 62 | 43 | 31 | 60 |
| Avg Precip (In.) | .44 | .31 | .36 | .68 | 1.42 | 1.1 | .58 | .46 | .81 | .59 | .36 | .33 | 7.44 |