Colorado planting zones & frost dates
USDA hardiness zones in Colorado go from 4b to 7a. 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 |
|---|---|---|---|
| Arvada | 6a | May 5 | Oct 5 |
| Aurora | 6a | May 4 | Oct 8 |
| Berkley | 6a | May 5 | Oct 5 |
| Black Forest | 5b | May 9 | Oct 6 |
| Boulder | 6a | May 6 | Oct 5 |
| Brighton | 5b | May 3 | Oct 7 |
| Broomfield | 6a | May 2 | Oct 11 |
| Castle Pines North | 5b | May 9 | Oct 2 |
| Castle Rock | 5b | May 9 | Oct 2 |
| Cañon City | 6a | May 4 | Oct 7 |
| Centennial | 6a | May 5 | Oct 8 |
| Cherry Creek | 6a | May 7 | Oct 8 |
| Clifton | 7a | Apr 23 | Oct 20 |
| Colorado Springs | 6a | May 3 | Oct 8 |
| Columbine | 6a | May 2 | Oct 11 |
| Commerce City | 6a | May 4 | Oct 8 |
| Dakota Ridge | 6a | May 2 | Oct 11 |
| Denver | 6a | Apr 30 | Oct 12 |
| Durango | 6b | May 21 | Oct 2 |
| Edwards | 5b | Jun 6 | Sep 14 |
| Englewood | 6a | May 2 | Oct 11 |
| Erie | 5b | May 7 | Oct 5 |
| Evans | 5b | May 2 | Oct 8 |
| Federal Heights | 6a | May 2 | Oct 11 |
| Firestone | 5b | May 7 | Oct 5 |
| Fort Carson | 6a | May 3 | Oct 8 |
| Fort Collins | 5b | May 2 | Oct 7 |
| Fort Morgan | 5b | May 6 | Oct 6 |
| Fountain | 6a | May 3 | Oct 8 |
| Frederick | 5b | May 7 | Oct 5 |
| Fruita | 7a | Apr 27 | Oct 11 |
| Golden | 6a | May 3 | Oct 14 |
| Grand Junction | 7a | Apr 14 | Oct 23 |
| Greeley | 5b | May 2 | Oct 8 |
| Greenwood Village | 6a | May 2 | Oct 11 |
| Highlands Ranch | 6a | May 5 | Oct 8 |
| Johnstown | 5b | May 10 | Oct 1 |
| Ken Caryl | 6a | May 2 | Oct 11 |
| Lafayette | 6a | May 2 | Oct 11 |
| Lakewood | 6a | May 3 | Oct 7 |
| Littleton | 6a | May 2 | Oct 11 |
| Lone Tree | 6a | May 5 | Oct 8 |
| Longmont | 5b | May 7 | Oct 5 |
| Louisville | 6a | May 6 | Oct 5 |
| Loveland | 5b | May 10 | Oct 1 |
| Montrose | 6b | Apr 28 | Oct 14 |
| Northglenn | 6a | May 2 | Oct 11 |
| Parker | 5b | May 9 | Oct 3 |
| Pueblo | 6a | Apr 30 | Oct 9 |
| Pueblo West | 6a | Apr 26 | Oct 13 |
| Security-Widefield | 6a | May 3 | Oct 8 |
| Sherrelwood | 6a | May 2 | Oct 11 |
| Steamboat Springs | 4b | Jun 9 | Sep 12 |
| Sterling | 5b | Apr 30 | Oct 9 |
| Superior | 6a | May 6 | Oct 5 |
| The Pinery | 5b | May 9 | Oct 3 |
| Thornton | 6a | May 2 | Oct 11 |
| Welby | 6a | May 2 | Oct 11 |
| Westminster | 6a | May 2 | Oct 11 |
| Wheat Ridge | 6a | May 5 | Oct 5 |
| Windsor | 5b | May 3 | Oct 6 |
Cities with 10,000+ residents. Data: USDA Plant Hardiness Zone Map 2023 and NOAA Climate Normals 1991–2020. Sources and method.