| 2023 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 5b: -15°F to -10°F Zone 4b: -25°F to -20°F Zone 4a: -30°F to -25°F | |
| 2012 Hardiness Zone: | Zone 3b: -35°F to -30°F Zone 5b: -15°F to -10°F Zone 4b: -25°F to -20°F Zone 5a: -20°F to -15°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 21 - May 31 | |
| Koppen-Geiger Climate Zone: | BSk - Cold Semi-Arid Climate | |
| Ecoregion: | 18a - Rolling Sagebrush Steppe | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 46 - 60 days Over 86°F |
Annual Climate Data for ZIP Code 82501 - Riverton, WY | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 2 | 8 | 20 | 29 | 38 | 46 | 52 | 49 | 39 | 28 | 14 | 3 | 27 |
| Avg Max Temp (°F) | 30 | 38 | 50 | 59 | 69 | 80 | 88 | 87 | 75 | 62 | 43 | 31 | 59 |
| Avg Precip (In.) | .28 | .25 | .48 | 1.04 | 1.82 | 1.16 | .76 | .51 | .9 | .82 | .46 | .35 | 8.83 |