Colorado frost dates
Median last spring frost and first fall frost for 402 places in Colorado. Last frost ranges from Apr 17 in Palisade to Jun 21 in Avon.
Largest cities
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Denver | Apr 30 | Oct 12 | 165 d | 6a |
| Colorado Springs | May 3 | Oct 8 | 158 d | 6a |
| Aurora | May 7 | Oct 8 | 154 d | 6a |
| Fort Collins | May 2 | Oct 7 | 158 d | 5b |
| Thornton | May 2 | Oct 11 | 162 d | 6a |
| Westminster | May 2 | Oct 11 | 162 d | 6a |
| Arvada | May 5 | Oct 5 | 153 d | 6a |
| Pueblo | Apr 30 | Oct 9 | 162 d | 6a |
| Greeley | May 2 | Oct 8 | 159 d | 5b |
| Boulder | May 6 | Oct 5 | 152 d | 6a |
| Longmont | May 7 | Oct 5 | 151 d | 5b |
| Loveland | May 10 | Oct 1 | 144 d | 5b |
| Broomfield | May 2 | Oct 11 | 162 d | 6a |
| Grand Junction | Apr 23 | Oct 20 | 180 d | 7a |
| Castle Rock | May 9 | Oct 2 | 146 d | 5b |
| Commerce City | May 4 | Oct 8 | 157 d | 6a |
| Parker | May 9 | Oct 3 | 147 d | 5b |
| Littleton | May 2 | Oct 11 | 162 d | 6a |
| Brighton | May 3 | Oct 7 | 157 d | 5b |
| Englewood | May 2 | Oct 11 | 162 d | 6a |
| Windsor | May 3 | Oct 6 | 156 d | 5b |
| Wheat Ridge | May 5 | Oct 5 | 153 d | 6a |
| Fountain | May 3 | Oct 8 | 158 d | 6a |
| Lafayette | May 2 | Oct 11 | 162 d | 6a |
| Erie | May 7 | Oct 5 | 151 d | 5b |
| Evans | May 2 | Oct 8 | 159 d | 5b |
| Louisville | May 6 | Oct 5 | 152 d | 6a |
| Golden | May 3 | Oct 7 | 157 d | 5b |
| Clifton | Apr 23 | Oct 20 | 180 d | 7a |
| Montrose | Apr 28 | Oct 14 | 169 d | 6b |
| Durango | May 21 | Oct 2 | 134 d | 6b |
| Canon City | May 4 | Oct 7 | 156 d | 6a |
| Johnstown | May 10 | Oct 1 | 144 d | 5b |
| Sterling | Apr 30 | Oct 9 | 162 d | 5b |
| Lone Tree | May 5 | Oct 8 | 156 d | 6a |
| Fruita | Apr 27 | Oct 11 | 167 d | 7a |
| Steamboat Springs | Jun 9 | Sep 12 | 95 d | 4b |
| Firestone | May 7 | Oct 5 | 151 d | 5b |
| Frederick | May 7 | Oct 5 | 151 d | 5b |
| Fort Morgan | May 6 | Oct 6 | 153 d | 5b |