Wyoming planting zones & frost dates
USDA hardiness zones in Wyoming go from 4a to 5b. Pick your city for its average frost dates and a planting calendar, or search by ZIP code.
| City | Zone | Avg. last frost | Avg. first frost |
|---|---|---|---|
| Casper | 5a | May 10 | Sep 29 |
| Cheyenne | 5b | May 14 | Oct 1 |
| Evanston | 5a | Jun 12 | Sep 12 |
| Gillette | 5a | May 15 | Oct 1 |
| Jackson | 4b | Jun 20 | Aug 31 |
| Laramie | 4a | Jun 7 | Sep 4 |
| Riverton | 4b | May 12 | Sep 24 |
| Rock Springs | 5a | May 24 | Sep 24 |
| Sheridan | 5a | May 21 | Sep 23 |
Cities with 10,000+ residents. Data: USDA Plant Hardiness Zone Map 2023 and NOAA Climate Normals 1991–2020. Sources and method.