Frost dates in Colorado
Across Colorado's 210 NOAA stations with a frost every year, the typical last spring frost ranges from April 14 at Grand Junction WFO (4,830 feet above sea level) to June 21 at Boulder 14 W (9,830 feet above sea level). The middle station's date is May 11.
Look up your ZIP code
Last frost across Colorado
The frost-free season runs from 71 days at Boulder 14 W to 190 days at Palisade.
The station with the latest frost sits about 5,000 feet higher than the one with the earliest.
At 24 stations, all high or far north, frost is possible in every month.
These are typical dates: in half of springs the last frost comes later. Each place's page, and each ZIP code lookup, also gives the late-year date, after which only 1 spring in 10 has a frost. That's the safer date for tender plants.
Frost dates for Colorado's larger places
| Place | Last spring frost | First fall frost | Season | Zone |
|---|---|---|---|---|
| Aurora | May 5 | October 9 | 156 days | 6a |
| Centennial | May 5 | October 8 | 154 days | 6a |
| Colorado Springs | May 3 | October 8 | 158 days | 6a |
| Denver | May 4 | October 8 | 156 days | 6a |
| Fort Collins | May 2 | October 7 | 157 days | 5b |
| Greeley | May 2 | October 8 | 159 days | 5b |
| Lakewood | May 3 | October 7 | 155 days | 6a |
| Pueblo | April 30 | October 9 | 161 days | 6a |
| Westminster | May 2 | October 11 | 160 days | 6a |
Typical (1-in-2) dates. Each place's page has the early and late years, a planting calendar and a printable planner. Zones are for the ZIP code nearest each place's center.
Hardiness zones in Colorado
Colorado's 626 ZIP codes in the USDA list fall in zones 4a to 7a: 4a (under 1 percent), 4b (2 percent), 5a (12 percent), 5b (35 percent), 6a (44 percent), 6b (6 percent) and 7a (2 percent). Compared with the 2012 map, 47 percent of them moved to a warmer half zone (25 by a full zone or more), 50 percent stayed the same and 18 moved to a colder one.
A hardiness zone is about the coldest night of winter, which decides which shrubs, trees and perennials survive. Frost dates are about spring and fall, which decide when to plant. You need both. Read more about what the zones mean and what changed in 2023.
Every NOAA station in Colorado
All 234 stations in Colorado with frost statistics in NOAA's 1991 to 2020 normals, from A to Z. Station names are usually a town, an airport, or a distance and direction from a town. Find one near you and at a similar elevation.
| Station | Elevation (feet) | Last spring frost | First fall frost | Season (days) |
|---|---|---|---|---|
| Akron 4 E | 4,540 | May 8 | October 6 | 149 |
| Akron Washington Co Airport | 4,660 | May 6 | October 8 | 155 |
| Alamosa 1 E | 7,540 | May 30 | September 17 | 108 |
| Alamosa San Luis Airport | 7,530 | June 7 | September 15 | 98 |
| Allenspark 3 NW | 8,500 | June 14 | September 12 | 92 |
| Altenbern | 5,640 | May 25 | September 25 | 120 |
| Antero Reservoir | 8,940 | Frost possible any month | 57 | |
| Arapahoe 12 S | 4,060 | May 5 | October 9 | 156 |
| Arapahoe 14 N | 4,140 | May 9 | October 7 | 150 |
| Aspen 1 SW | 8,180 | June 2 | September 23 | 113 |
| Aspen Pitkin Co Airport | 7,720 | May 31 | September 23 | 114 |
| Bailey | 7,750 | June 16 | September 8 | 84 |
| Black Canyon of the Gunnison | 8,150 | May 23 | October 1 | 130 |
| Black Forest 6 WNW | 6,960 | May 11 | October 6 | 147 |
| Blanca 4 NW | 7,710 | May 25 | September 22 | 117 |
| Blue Mesa Lake | 7,570 | June 9 | September 16 | 96 |
| Bonham Reservoir | 9,850 | Frost possible any month | 79 | |
| Bonny Dam 2 NE | 3,720 | May 5 | October 10 | 155 |
| Boulder | 5,490 | May 6 | October 5 | 151 |
| Boulder 14 W | 9,830 | June 21 | September 2 | 71 |
| Briggsdale | 4,860 | May 12 | September 28 | 135 |
| Brighton 3 SE | 5,020 | May 3 | October 7 | 155 |
| Buckhorn Mountain 1 E | 7,400 | May 21 | September 29 | 128 |
| Buena Vista 2 S | 7,950 | May 27 | September 23 | 116 |
| Burlington | 4,160 | May 6 | October 9 | 155 |
| Burlington Carson Airport | 4,190 | May 2 | October 10 | 160 |
| Byers 5 ENE | 5,100 | May 13 | October 2 | 142 |
| Cabin Creek | 10,020 | June 6 | September 19 | 103 |
| Campo 7 S | 4,100 | April 29 | October 13 | 166 |
| Canon City | 5,380 | May 4 | October 7 | 153 |
| Castle Rock | 6,180 | May 9 | October 2 | 143 |
| Cedaredge 3 E | 6,840 | May 3 | October 9 | 156 |
| Center 4 SSW | 7,670 | May 24 | September 24 | 120 |
| Cheesman | 6,880 | May 17 | October 1 | 135 |
| Cheraw 1 N | 4,150 | April 30 | October 10 | 163 |
| Cherry Creek Dam | 5,650 | May 7 | October 8 | 152 |
| Cheyenne Wells 2 NE | 4,200 | May 1 | October 14 | 165 |
| Cimarron | 6,890 | June 20 | September 10 | 81 |
| Climax | 11,350 | Frost possible any month | 61 | |
| Coal Creek Canyon | 8,950 | June 5 | September 16 | 103 |
| Cochetopa Creek | 8,010 | June 21 | September 5 | 74 |
| Collbran 1 WSW | 6,010 | May 17 | September 30 | 136 |
| Colorado NM | 5,780 | April 26 | October 16 | 172 |
| Colorado Springs Municipal Airport | 6,180 | May 3 | October 8 | 158 |
| Cortez | 6,170 | May 12 | October 7 | 147 |
| Cortez 8 SE | 8,030 | May 6 | October 14 | 158 |
| Cortez Montezuma Co Airport | 5,920 | May 27 | September 28 | 125 |
| Craig 4 SW | 6,500 | May 29 | September 20 | 113 |
| Craig Moffat Co Airport | 6,190 | June 6 | September 12 | 96 |
| Creede | 8,850 | Frost possible any month | 81 | |
| Creede WTP | 8,630 | Frost possible any month | 59 | |
| Crested Butte | 8,870 | Frost possible any month | 47 | |
| Crestone 2 SE | 8,010 | May 26 | September 26 | 120 |
| Cripple Creek 3 NNW | 9,240 | May 26 | September 26 | 121 |
| Crook | 3,710 | May 11 | October 4 | 145 |
| Cumbre Vista - Colorado Springs 1 | 6,940 | May 9 | October 6 | 150 |
| Del Norte 3 ENE | 7,840 | May 23 | September 25 | 123 |
| Delta 3 E | 5,030 | May 1 | October 7 | 159 |
| Denver Centennial Airport | 5,880 | May 5 | October 8 | 154 |
| Denver International Airport | 5,410 | May 5 | October 9 | 156 |
| Denver Water Dept | 5,230 | April 30 | October 12 | 165 |
| Denver-Stapleton | 5,290 | May 4 | October 8 | 156 |
| Dillon 1 E | 9,060 | Frost possible any month | 41 | |
| Dinosaur 2 E | 6,060 | May 2 | October 14 | 161 |
| Dinosaur NM | 5,960 | May 12 | October 5 | 146 |
| Divide 4 NW | 9,130 | June 1 | September 21 | 110 |
| Dove Creek | 6,860 | May 11 | October 12 | 152 |
| Durango | 6,760 | May 21 | October 2 | 134 |
| Durango La Plata Co Airport | 6,660 | June 1 | September 27 | 116 |
| Eads | 4,210 | April 30 | October 13 | 165 |
| Eastonville 2 NNW | 7,210 | May 29 | September 21 | 114 |
| Elizabeth 2 NW | 6,610 | May 16 | October 2 | 137 |
| Ellicott 7 S | 5,740 | May 6 | October 3 | 149 |
| Estes Park 3 SSE | 7,810 | May 30 | September 17 | 109 |
| Evergreen | 6,980 | May 23 | September 22 | 118 |
| Fairplay S Park Road | 10,000 | June 16 | September 9 | 83 |
| Flagler 1 S | 4,920 | May 5 | October 8 | 155 |
| Fleming 3 SW | 4,260 | May 4 | October 11 | 157 |
| Florissant Fossil Bed | 8,400 | Frost possible any month | 68 | |
| Fort Collins | 5,000 | May 2 | October 7 | 157 |
| Fort Collins 4 E | 4,920 | May 3 | October 6 | 154 |
| Fort Lewis | 7,610 | June 1 | September 27 | 116 |
| Fort Morgan | 4,380 | May 6 | October 6 | 153 |
| Fraser | 8,560 | Frost possible any month | 32 | |
| Fruita | 4,500 | April 27 | October 11 | 164 |
| Gateway 1 ENE | 4,670 | April 20 | October 21 | 182 |
| Genoa | 5,590 | May 8 | October 10 | 155 |
| Georgetown | 8,520 | May 30 | September 19 | 112 |
| Glade Park 17 W | 6,320 | May 21 | September 26 | 126 |
| Glenwood Springs #2 | 5,900 | May 13 | October 3 | 142 |
| Gould 4 SE SFSP | 9,000 | Frost possible any month | 51 | |
| Grand Junction 6 ESE | 4,760 | April 23 | October 20 | 179 |
| Grand Junction Walker Field | 4,860 | April 28 | October 16 | 171 |
| Grand Junction WFO | 4,830 | April 14 | October 23 | 190 |
| Grand Lake 1 NW | 8,720 | Frost possible any month | 54 | |
| Grand Lake 6 SSW | 8,290 | June 13 | September 7 | 84 |
| Grant | 8,670 | June 15 | September 9 | 84 |
| Great Sand Dunes NP & Preserve | 8,180 | May 21 | October 1 | 131 |
| Greeley Unc | 4,710 | May 2 | October 8 | 159 |
| Green Mount Dam | 7,740 | June 6 | September 14 | 98 |
| Gross Reservoir | 7,970 | May 24 | September 23 | 120 |
| Guffey 9 SE | 8,910 | May 19 | October 2 | 134 |
| Gunnison 3 SW | 7,620 | Frost possible any month | 75 | |
| Hayden | 6,470 | June 1 | September 20 | 109 |
| Hermit 8 SE | 8,950 | Frost possible any month | 62 | |
| Hohnholz Ranch | 7,800 | Frost possible any month | 56 | |
| Holly | 3,400 | May 1 | October 12 | 163 |
| Holyoke | 3,780 | May 11 | October 3 | 144 |
| Hourglass Reservoir | 9,520 | Frost possible any month | 69 | |
| Hugo 1 NW | 5,030 | May 10 | October 2 | 143 |
| Idalia | 3,970 | May 4 | October 9 | 155 |
| Ignacio 6 ESE | 6,550 | May 23 | September 29 | 128 |
| Joes | 4,270 | May 3 | October 9 | 158 |
| John Martin Dam | 3,820 | April 24 | October 15 | 172 |
| Julesburg | 3,480 | May 7 | October 6 | 152 |
| Karval | 5,080 | May 9 | October 6 | 149 |
| Kassler | 5,590 | May 8 | October 3 | 147 |
| Kim 10 SSE | 5,260 | April 24 | October 18 | 175 |
| Kim 15 NNE | 5,190 | May 5 | October 9 | 156 |
| Kit Carson | 4,300 | May 10 | October 1 | 142 |
| Kit Carson 9 NNE | 4,350 | May 7 | October 6 | 151 |
| Kremmling | 7,460 | June 14 | September 5 | 80 |
| La Junta | 4,090 | April 26 | October 15 | 171 |
| La Junta 17 WSW | 4,390 | May 8 | October 4 | 148 |
| La Junta 20 S | 4,210 | April 27 | October 14 | 168 |
| La Junta Municipal Airport | 4,190 | April 24 | October 15 | 173 |
| Lake City | 8,670 | June 8 | September 17 | 101 |
| Lake City 1 NNE | 8,710 | June 9 | September 17 | 99 |
| Lake George 8 SW | 8,550 | June 2 | September 19 | 108 |
| Lakewood | 5,640 | May 3 | October 7 | 155 |
| Lamar | 3,630 | April 30 | October 10 | 163 |
| Lamar Municipal Airport | 3,700 | May 2 | October 7 | 157 |
| Las Animas | 3,890 | April 29 | October 12 | 166 |
| Leadville Lake Co Airport | 9,930 | Frost possible any month | 52 | |
| Lemon Dam | 8,110 | May 28 | September 30 | 122 |
| Leroy 5 WSW | 4,470 | May 10 | October 6 | 147 |
| Limon Wsmo | 5,360 | May 21 | September 26 | 127 |
| Lindon 5 WNW | 4,850 | May 15 | October 2 | 139 |
| Longmont 2 ESE | 4,950 | May 7 | October 5 | 151 |
| Loveland 2 N | 5,080 | May 10 | October 1 | 142 |
| Manassa | 7,690 | May 28 | September 21 | 115 |
| Mancos 1 SW | 6,900 | June 4 | September 24 | 111 |
| Marston Filter Plant | 5,610 | May 2 | October 11 | 160 |
| Massadona 3 E | 6,140 | May 10 | October 4 | 147 |
| Matheson 8 SE | 5,830 | May 12 | October 2 | 141 |
| Maybell | 5,940 | June 16 | September 9 | 83 |
| Meeker | 6,230 | June 4 | September 16 | 104 |
| Meeker Airport | 6,390 | May 30 | September 22 | 117 |
| Meredith | 7,820 | Frost possible any month | 55 | |
| Mesa Verde NP | 7,140 | May 9 | October 14 | 156 |
| Monte Vista 2 W | 7,690 | June 11 | September 13 | 92 |
| Montrose #2 | 5,790 | April 28 | October 14 | 167 |
| Montrose 11 ENE | 8,400 | May 20 | October 1 | 132 |
| Montrose Regional Airport | 5,760 | May 2 | October 8 | 157 |
| Monument | 7,080 | May 14 | October 1 | 138 |
| Monument 3 S | 6,820 | May 17 | October 1 | 136 |
| New Raymer | 4,780 | May 9 | October 4 | 146 |
| New Raymer 21 N | 5,180 | May 18 | September 29 | 133 |
| Northdale | 6,680 | June 3 | September 25 | 113 |
| Northglenn | 5,410 | May 2 | October 11 | 160 |
| Norwood | 7,020 | May 25 | October 1 | 128 |
| Norwood #2 | 7,010 | May 21 | October 1 | 131 |
| Nunn 7 NNE | 5,390 | May 13 | September 27 | 136 |
| Ordway 1 ENE | 4,310 | May 2 | October 8 | 159 |
| Ordway 21 N | 4,770 | May 3 | October 7 | 155 |
| Ouray | 7,840 | May 17 | October 1 | 137 |
| Ouray #2 | 7,720 | May 18 | October 4 | 139 |
| Palisade | 4,750 | April 17 | October 26 | 190 |
| Paonia 1 SW | 5,580 | May 3 | October 12 | 159 |
| Paradox 2 N | 5,450 | May 11 | October 5 | 146 |
| Parker | 5,910 | May 9 | October 3 | 145 |
| Placerville | 7,380 | May 26 | September 29 | 125 |
| Pueblo Mem Airport | 4,720 | April 30 | October 9 | 161 |
| Pueblo Reservoir | 4,860 | April 26 | October 13 | 166 |
| Ralston Reservoir | 5,900 | May 3 | October 14 | 161 |
| Rangely 1 E | 5,280 | May 15 | October 1 | 136 |
| Ridgway | 7,050 | June 11 | September 13 | 92 |
| Rifle 3 ENE | 5,470 | May 23 | September 25 | 124 |
| Rifle Garfield Co Airport | 5,530 | May 11 | October 4 | 143 |
| Rio Grande Reservoir | 9,490 | June 15 | September 11 | 85 |
| Rocky Ford 2 SE | 4,170 | May 1 | October 8 | 159 |
| Roxborough SP | 6,120 | May 16 | October 1 | 136 |
| Rush 1 N | 6,050 | May 9 | October 4 | 146 |
| Rustic 9 WSW | 7,700 | June 5 | September 16 | 101 |
| Ruxton Park | 9,060 | June 3 | September 17 | 102 |
| Rye 1 SW | 7,140 | May 5 | October 10 | 156 |
| Saguache | 7,700 | May 16 | September 28 | 135 |
| Salida | 7,160 | May 29 | September 20 | 112 |
| San Luis 1 S | 7,940 | May 31 | September 23 | 115 |
| Santa Maria Reservoir | 9,690 | Frost possible any month | 64 | |
| Sargents | 8,460 | Frost possible any month | 33 | |
| Sedgwick 5 S | 4,000 | May 6 | October 7 | 152 |
| Seibert | 4,700 | May 4 | October 11 | 158 |
| Shaw 4 ENE | 5,000 | May 12 | October 4 | 143 |
| Sheep Mountain | 7,740 | May 27 | September 25 | 119 |
| Sheridan Lake | 4,070 | April 27 | October 15 | 170 |
| Sheridan Lake 4 E | 4,040 | April 28 | October 13 | 167 |
| Shoshone | 5,990 | May 1 | October 14 | 164 |
| Silverton | 9,280 | Frost possible any month | 40 | |
| Spicer | 8,390 | Frost possible any month | 53 | |
| Springfield Comanche | 4,380 | May 3 | October 10 | 158 |
| Steamboat Springs | 6,870 | June 9 | September 12 | 93 |
| Sterling | 3,970 | April 30 | October 9 | 161 |
| Stratton | 4,400 | May 6 | October 9 | 155 |
| Strontia Springs Dam | 5,840 | May 16 | September 29 | 132 |
| Sugarloaf Reservoir | 9,740 | Frost possible any month | 53 | |
| Tacony 13 SE | 4,880 | May 5 | October 6 | 153 |
| Taylor Park | 9,180 | June 20 | September 8 | 80 |
| Telluride 4 WNW | 8,650 | Frost possible any month | 60 | |
| Trinidad | 6,030 | April 30 | October 15 | 167 |
| Trinidad Lake | 6,310 | May 11 | October 4 | 145 |
| Trinidad Perry Stokes Airport | 5,740 | May 4 | October 9 | 156 |
| Twin Lakes Reservoir | 9,240 | June 16 | September 10 | 85 |
| Uravan | 5,020 | April 26 | October 18 | 174 |
| Vail | 8,300 | June 21 | September 7 | 77 |
| Vallecito Dam | 7,640 | May 31 | September 26 | 119 |
| Vallecito Reservoir | 7,670 | May 18 | October 11 | 145 |
| Virginia Dale 7 ENE | 7,010 | May 31 | September 19 | 110 |
| Walden | 8,060 | Frost possible any month | 31 | |
| Walsenburg 1 NW | 6,290 | May 6 | October 4 | 149 |
| Walsh 1 W | 3,980 | April 30 | October 14 | 166 |
| Waterdale | 5,230 | May 12 | October 1 | 141 |
| Waverly 1 W | 7,600 | June 6 | September 15 | 100 |
| Westcliffe | 7,870 | June 11 | September 9 | 89 |
| WFO Pueblo | 4,650 | April 30 | October 9 | 162 |
| Wheat Ridge 2 | 5,400 | May 5 | October 5 | 151 |
| Wild Horse 6 N | 4,660 | May 4 | October 8 | 155 |
| Williams Fork Dam | 7,620 | June 12 | September 10 | 89 |
| Woodrow 6 NNE | 4,370 | May 15 | October 1 | 140 |
| Wray | 3,550 | May 7 | October 6 | 151 |
| Yampa | 7,860 | June 14 | September 11 | 89 |
| Yellow Jacket 2 W | 6,930 | May 17 | October 9 | 145 |
| Yellow Jacket 4 NE | 7,090 | May 15 | October 8 | 147 |
| Yuma | 4,130 | May 1 | October 12 | 164 |
Typical (1-in-2) dates at 32°F. For the early and late years, and a planting calendar built from your own dates, look up your ZIP code.