NOAA 1991–2020 freeze normals
Frost Dates in Colorado
Last and first frost at the 111 NOAA stations behind this site's Colorado pages.
At the middle station of the 111 in Colorado where a freeze comes every year, the last spring frost (50%) is May 13 and the first fall frost October 2, a freeze-free season of 142 days. The last frost is earliest at Grand Junction (Grand Junction WFO, CO, April 14) and latest at Nederland (Boulder 14 W, CO, June 21), 68 days apart. The season runs from 71 days at Nederland to 190 at Palisade.
78 of these stations were also in NOAA's previous normals, for 1981–2010. Between the two, the median station's freeze-free season grew 2 days longer and the first fall frost 2 days later; the season lengthened at 53 stations and shortened at 18. The two periods share twenty years, so the change reflects mostly 2011–2020 against 1981–1990.
Colorado places by frost date
| Place | ZIP | Last frost | First frost | Season | Winters with 32°F |
|---|---|---|---|---|---|
| Parker | 80134 | May 9 | October 3 | 145 d | 100% |
| Aurora | 80013 | May 7 | October 8 | 152 d | 100% |
| Greeley | 80634 | May 2 | October 8 | 159 d | 100% |
| Longmont | 80504 | May 7 | October 5 | 151 d | 100% |
| Denver | 80219 | April 30 | October 12 | 165 d | 100% |
| Commerce City | 80022 | May 4 | October 8 | 156 d | 100% |
| Thornton | 80229 | May 2 | October 11 | 160 d | 100% |
| Fort Collins | 80525 | May 3 | October 6 | 154 d | 100% |
| Loveland | 80538 | May 10 | October 1 | 142 d | 100% |
| Colorado Springs | 80918 | May 9 | October 6 | 150 d | 100% |
| Littleton | 80123 | May 2 | October 11 | 160 d | 100% |
| Highlands Ranch | 80126 | May 5 | October 8 | 154 d | 100% |
| Fort Collins | 80526 | May 2 | October 7 | 157 d | 100% |
| Golden | 80401 | May 3 | October 7 | 155 d | 100% |
| Thornton | 80602 | May 3 | October 7 | 155 d | 100% |
| Denver | 80249 | May 5 | October 9 | 156 d | 100% |
| Colorado Springs | 80916 | May 3 | October 8 | 158 d | 100% |
| Castle Rock | 80104 | May 9 | October 2 | 143 d | 100% |
| Arvada | 80003 | May 5 | October 5 | 151 d | 100% |
| Pueblo West | 81007 | April 26 | October 13 | 166 d | 100% |
| Louisville | 80027 | May 6 | October 5 | 151 d | 100% |
| Canon City | 81212 | May 4 | October 7 | 153 d | 100% |
| Grand Junction | 81504 | April 14 | October 23 | 190 d | 100% |
| Pueblo | 81001 | April 30 | October 9 | 162 d | 100% |
| Durango | 81301 | May 21 | October 2 | 134 d | 100% |
| Highlands Ranch | 80129 | May 8 | October 3 | 147 d | 100% |
| Monument | 80132 | May 14 | October 1 | 138 d | 100% |
| Colorado Springs | 80919 | May 11 | October 6 | 147 d | 100% |
| Colorado Springs | 80921 | May 17 | October 1 | 136 d | 100% |
| Evergreen | 80439 | May 23 | September 22 | 118 d | 100% |
| Montrose | 81401 | April 28 | October 14 | 167 d | 100% |
| Colorado Springs | 80904 | June 3 | September 17 | 102 d | 100% |
| Golden | 80403 | May 3 | October 14 | 161 d | 100% |
| Steamboat Springs | 80487 | June 9 | September 12 | 93 d | 100% |
| Sterling | 80751 | April 30 | October 9 | 161 d | 100% |
| Colorado Springs | 80924 | June 21 | September 7 | 77 d | 100% |
| Fruita | 81521 | April 27 | October 11 | 164 d | 100% |
| Fort Morgan | 80701 | May 6 | October 6 | 153 d | 100% |
| Carbondale | 81623 | May 13 | October 3 | 142 d | 100% |
| Grand Junction | 81507 | April 26 | October 16 | 172 d | 100% |
| Alamosa | 81101 | May 30 | September 17 | 108 d | 100% |
| Elizabeth | 80107 | May 16 | October 2 | 137 d | 100% |
| Cortez | 81321 | May 12 | October 7 | 147 d | 100% |
| Delta | 81416 | May 1 | October 7 | 159 d | 100% |
| Rifle | 81650 | May 23 | September 25 | 124 d | 100% |
| Clifton | 81520 | April 23 | October 20 | 179 d | 100% |
| Pagosa Springs | 81147 | June 9 | September 22 | 103 d | 100% |
| Woodland Park | 80863 | June 1 | September 21 | 110 d | 100% |
| Craig | 81625 | June 6 | September 12 | 96 d | 100% |
| Grand Junction | 81505 | April 28 | October 16 | 171 d | 100% |
| Trinidad | 81082 | April 30 | October 15 | 167 d | 100% |
| Gunnison | 81230 | June 21 | September 5 | 74 d | 100% |
| Gypsum | 81637 | May 1 | October 14 | 164 d | 100% |
| Estes Park | 80517 | May 30 | September 17 | 109 d | 100% |
| Breckenridge | 80424 | June 16 | September 9 | 83 d | 100% |
| La Junta | 81050 | April 26 | October 15 | 171 d | 100% |
| Durango | 81303 | June 1 | September 27 | 116 d | 100% |
| Salida | 81201 | May 29 | September 20 | 112 d | 100% |
| Aspen | 81611 | June 2 | September 23 | 113 d | 100% |
| Lamar | 81052 | April 30 | October 10 | 163 d | 100% |
| Bayfield | 81122 | May 31 | September 26 | 119 d | 100% |
| Bailey | 80421 | June 16 | September 8 | 84 d | 100% |
| Dillon | 80435 | June 6 | September 19 | 103 d | 100% |
| Buena Vista | 81211 | May 27 | September 23 | 116 d | 100% |
| Parachute | 81635 | May 25 | September 25 | 120 d | 100% |
| Leadville | 80461 | June 16 | September 10 | 85 d | 100% |
| Brush | 80723 | May 15 | October 1 | 140 d | 100% |
| Monte Vista | 81144 | June 11 | September 13 | 92 d | 100% |
| Calhan | 80808 | May 9 | October 4 | 146 d | 100% |
| Silt | 81652 | May 11 | October 4 | 143 d | 100% |
| Basalt | 81621 | May 31 | September 23 | 114 d | 100% |
| Strasburg | 80136 | May 13 | October 2 | 142 d | 100% |
| Ignacio | 81137 | May 23 | September 29 | 128 d | 100% |
| Telluride | 81435 | May 26 | September 29 | 125 d | 100% |
| Rocky Ford | 81067 | May 1 | October 8 | 159 d | 100% |
| Cedaredge | 81413 | May 3 | October 9 | 156 d | 100% |
| Palisade | 81526 | April 17 | October 26 | 190 d | 100% |
| Dolores | 81323 | May 15 | October 8 | 147 d | 100% |
| Olathe | 81425 | May 2 | October 8 | 157 d | 100% |
| Walsenburg | 81089 | May 6 | October 4 | 149 d | 100% |
| Las Animas | 81054 | April 29 | October 12 | 166 d | 100% |
| Yuma | 80759 | May 1 | October 12 | 164 d | 100% |
| Lyons | 80540 | June 14 | September 12 | 92 d | 100% |
| Elbert | 80106 | May 29 | September 21 | 114 d | 100% |
| Westcliffe | 81252 | June 11 | September 9 | 89 d | 100% |
| Black Hawk | 80422 | June 5 | September 16 | 103 d | 100% |
| Sedalia | 80135 | May 16 | October 1 | 136 d | 100% |
| Ault | 80610 | May 13 | September 27 | 136 d | 100% |
| Mancos | 81328 | June 4 | September 24 | 111 d | 100% |
| Burlington | 80807 | May 6 | October 9 | 155 d | 100% |
| Paonia | 81428 | May 3 | October 12 | 159 d | 100% |
| Meeker | 81641 | June 4 | September 16 | 104 d | 100% |
| Granby | 80446 | June 13 | September 7 | 84 d | 100% |
| Center | 81125 | May 24 | September 24 | 120 d | 100% |
| Wray | 80758 | May 7 | October 6 | 151 d | 100% |
| Nederland | 80466 | June 21 | September 2 | 71 d | 100% |
| Crested Butte | 81224 | June 20 | September 8 | 80 d | 100% |
| Del Norte | 81132 | May 23 | September 25 | 123 d | 100% |
| Idaho Springs | 80452 | May 30 | September 19 | 112 d | 100% |
| Ridgway | 81432 | June 11 | September 13 | 92 d | 100% |
| Ordway | 81063 | May 2 | October 8 | 159 d | 100% |
| Holyoke | 80734 | May 11 | October 3 | 144 d | 100% |
| Rangely | 81648 | May 15 | October 1 | 136 d | 100% |
| Kremmling | 80459 | June 14 | September 5 | 80 d | 100% |
| Hesperus | 81326 | June 1 | September 27 | 116 d | 100% |
| Hayden | 81639 | June 1 | September 20 | 109 d | 100% |
| Limon | 80828 | May 21 | September 26 | 127 d | 100% |
| Oak Creek | 80467 | June 14 | September 11 | 89 d | 100% |
| Livermore | 80536 | May 31 | September 19 | 110 d | 100% |
| Akron | 80720 | May 8 | October 6 | 149 d | 100% |
| Laporte | 80535 | May 21 | September 29 | 128 d | 100% |
50% dates from NOAA NCEI U.S. Climate Normals 1991–2020, one row per station; a state page is published when at least 5 stations stand behind its pages. Where a freeze comes in fewer than nine winters in ten, the dates describe the winters that have one.