| 2023 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 4b: -25°F to -20°F Zone 6a: -10°F to -5°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 4b: -25F to -20F | |
| 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: | 43w - Powder River Basin | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 31 - 45 days Over 86°F |
Annual Climate Data for ZIP Code 82716 - Gillette, WY | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 8 | 14 | 21 | 29 | 39 | 48 | 54 | 53 | 42 | 31 | 19 | 10 | 31 |
| Avg Max Temp (°F) | 31 | 38 | 46 | 56 | 66 | 77 | 86 | 85 | 73 | 60 | 43 | 34 | 58 |
| Avg Precip (In.) | .44 | .46 | .84 | 1.69 | 2.72 | 2.52 | 1.73 | 1.27 | 1.27 | 1.41 | .59 | .52 | 15.47 |