Colorado Frost Dates: Last and First Frost by Town

234 NOAA weather stations · 1991–2020 U.S. Climate Normals · Data updated 2026-10-29

Quick answer

Across Colorado's 210 NOAA stations with regular frost, the median last spring frost is May 11 and the median first fall frost is October 4. Last frost dates range from April 14 at Grand Junction WFO to June 21 at Vail, so enter your ZIP code below for the station nearest you.

How frost dates vary across Colorado

Elevation matters: across Colorado's stations, each 1,000 ft of elevation delays the median last frost by about 8 days.
North vs south: stations in the northern third of the state (north of 39.6°N) reach their median last frost about 5 days earlier than the southern third (south of 38.5°N).
Safety margin: the median 10%-risk date (May 27) is about 16 days after the median last frost. Waiting until then cuts the chance of a killing frost on tender transplants from 1 in 2 to 1 in 10.

Frost dates at Colorado's major weather stations

These National Weather Service stations, mostly at airports, have the longest and most complete records in the state.


Akron Washington County Airport	4,663	May 6	May 19	Oct 8	155
Alamosa San Luis Airport	7,533	Jun 7	Jun 24	Sep 15	98
Aspen Pitkin County Airport	7,720	May 31	Jun 14	Sep 23	114
Boulder 14 W	9,828	Jun 21	Jul 4	Sep 2	71
Burlington Carson Airport	4,192	May 2	May 16	Oct 10	160
Colorado Springs Municipal Airport	6,181	May 3	May 15	Oct 8	158
Cortez 8 SE	8,034	May 6	May 27	Oct 14	158
Cortez Montezuma County Airport	5,914	May 27	Jun 11	Sep 28	125
Craig Moffat County Airport	6,186	Jun 6	Jun 24	Sep 12	96
Denver Centennial Airport	5,883	May 5	May 17	Oct 8	154
Denver Intl Airport	5,414	May 5	May 19	Oct 9	156
Denver-stapleton	5,286	May 4	May 16	Oct 8	156
Dinosaur 2 E	6,062	May 2	May 17	Oct 14	161
Durango La Plata County Airport	6,660	Jun 1	Jun 15	Sep 27	116
Grand Junction Walker Field	4,858	Apr 28	May 14	Oct 16	171
La Junta 17 WSW	4,386	May 8	May 25	Oct 4	148
La Junta Municipal Airport	4,194	Apr 24	May 6	Oct 15	173
Lamar Municipal Airport	3,704	May 2	May 17	Oct 7	157
Leadville Lake County Airport	9,932	Any month	Any month	Any month	52
Limon Wsmo	5,364	May 21	Jun 4	Sep 26	127
Meeker Airport	6,390	May 30	Jun 13	Sep 22	117
Montrose 11 ENE	8,402	May 20	Jun 4	Oct 1	132
Montrose Regional Airport	5,759	May 2	May 17	Oct 8	157
Nunn 7 NNE	5,390	May 13	May 27	Sep 27	136
Pueblo Memorial Airport	4,720	Apr 30	May 12	Oct 9	161
Rifle Garfield County Airport	5,530	May 11	May 27	Oct 4	143
Springfield Comanche	4,383	May 3	May 17	Oct 10	158
Trinidad Perry Stokes Airport	5,741	May 4	May 19	Oct 9	156

All 234 stations in Colorado

Last frost and first frost are medians: a 50% chance of a 32°F night after (spring) or before (fall) that date. 10% risk is the spring date with only a 1-in-10 chance of a later frost. Click a column to sort.

Filter by station name


Akron 4 E	4,542	May 8	May 22	Oct 6	149
Akron Washington County Airport	4,663	May 6	May 19	Oct 8	155
Alamosa 1E	7,540	May 30	Jun 13	Sep 17	108
Alamosa San Luis Airport	7,533	Jun 7	Jun 24	Sep 15	98
Allenspark 3NW	8,500	Jun 14	Jun 28	Sep 12	92
Altenbern	5,637	May 25	Jun 13	Sep 25	120
Antero Rsvr	8,939	Any month	Any month	Any month	57
Arapahoe 12S	4,065	May 5	May 19	Oct 9	156
Arapahoe 14N	4,142	May 9	May 22	Oct 7	150
Aspen 1SW	8,175	Jun 2	Jun 17	Sep 23	113
Aspen Pitkin County Airport	7,720	May 31	Jun 14	Sep 23	114
Bailey	7,752	Jun 16	Jul 1	Sep 8	84
Black Canyon Of The Gunnison	8,151	May 23	Jun 9	Oct 1	130
Black Forest 6WNW	6,957	May 11	May 25	Oct 6	147
Blanca 4 NW	7,709	May 25	Jun 12	Sep 22	117
Blue Mesa Lake	7,568	Jun 9	Jun 24	Sep 16	96
Bonham Rsvr	9,852	Any month	Any month	Any month	79
Bonny Dam 2NE	3,717	May 5	May 19	Oct 10	155
Boulder	5,484	May 6	May 18	Oct 5	151
Boulder 14 W	9,828	Jun 21	Jul 4	Sep 2	71
Briggsdale	4,862	May 12	May 25	Sep 28	135
Brighton 3 SE	5,016	May 3	May 16	Oct 7	155
Buckhorn Mountain 1 E	7,400	May 21	Jun 4	Sep 29	128
Buena Vista 2S	7,954	May 27	Jun 11	Sep 23	116
Burlington	4,162	May 6	May 19	Oct 9	155
Burlington Carson Airport	4,192	May 2	May 16	Oct 10	160
Byers 5 ENE	5,101	May 13	May 30	Oct 2	142
Cabin Creek	10,020	Jun 6	Jun 21	Sep 19	103
Campo 7 S	4,105	Apr 29	May 12	Oct 13	166
Canon City	5,378	May 4	May 18	Oct 7	153
Castle Rock	6,185	May 9	May 24	Oct 2	143
Cedaredge 3E	6,838	May 3	May 21	Oct 9	156
Center 4 SSW	7,673	May 24	Jun 8	Sep 24	120
Cheesman	6,880	May 17	Jun 6	Oct 1	135
Cheraw 1 N	4,147	Apr 30	May 13	Oct 10	163
Cherry Creek Dam	5,647	May 7	May 21	Oct 8	152
Cheyenne Wells 2NE	4,203	May 1	May 17	Oct 14	165
Cimarron	6,890	Jun 20	Jul 7	Sep 10	81
Climax	11,344	Any month	Any month	Any month	61
Coal Creek Canyon	8,950	Jun 5	Jun 19	Sep 16	103
Cochetopa Creek	8,006	Jun 21	Jul 7	Sep 5	74
Collbran 1WSW	6,009	May 17	Jun 3	Sep 30	136
Colorado National Monument	5,781	Apr 26	May 15	Oct 16	172
Colorado Springs Municipal Airport	6,181	May 3	May 15	Oct 8	158
Cortez	6,167	May 12	May 31	Oct 7	147
Cortez 8 SE	8,034	May 6	May 27	Oct 14	158
Cortez Montezuma County Airport	5,914	May 27	Jun 11	Sep 28	125
Craig 4SW	6,496	May 29	Jun 13	Sep 20	113
Craig Moffat County Airport	6,186	Jun 6	Jun 24	Sep 12	96
Creede	8,852	Any month	Any month	Any month	81
Creede Wtp	8,624	Any month	Any month	Any month	59
Crested Butte	8,867	Any month	Any month	Any month	47
Crestone 2 SE	8,004	May 26	Jun 9	Sep 26	120
Cripple Creek 3NNW	9,235	May 26	Jun 9	Sep 26	121
Crook	3,709	May 11	May 23	Oct 4	145
Cumbre Vista - Colorado Springs 1	6,942	May 9	May 20	Oct 6	150
Del Norte 3ENE	7,845	May 23	Jun 8	Sep 25	123
Delta 3E	5,027	May 1	May 14	Oct 7	159
Denver Centennial Airport	5,883	May 5	May 17	Oct 8	154
Denver Intl Airport	5,414	May 5	May 19	Oct 9	156
Denver Water Dept	5,228	Apr 30	May 13	Oct 12	165
Denver-stapleton	5,286	May 4	May 16	Oct 8	156
Dillon 1 E	9,065	Any month	Any month	Any month	41
Dinosaur 2 E	6,062	May 2	May 17	Oct 14	161
Dinosaur National Monument	5,960	May 12	Jun 1	Oct 5	146
Divide 4NW	9,134	Jun 1	Jun 17	Sep 21	110
Dove Creek	6,863	May 11	May 25	Oct 12	152
Durango	6,761	May 21	Jun 7	Oct 2	134
Durango La Plata County Airport	6,660	Jun 1	Jun 15	Sep 27	116
Eads	4,212	Apr 30	May 12	Oct 13	165
Eastonville 2 NNW	7,210	May 29	Jun 13	Sep 21	114
Elizabeth 2NW	6,611	May 16	Jun 1	Oct 2	137
Ellicott 7S	5,739	May 6	May 28	Oct 3	149
Estes Park 3 SSE	7,812	May 30	Jun 14	Sep 17	109
Evergreen	6,985	May 23	Jun 10	Sep 22	118
Fairplay S Park Rd	9,995	Jun 16	Jun 30	Sep 9	83
Flagler 1S	4,921	May 5	May 20	Oct 8	155
Fleming 3SW	4,256	May 4	May 16	Oct 11	157
Florissant Fossil Bed	8,402	Any month	Any month	Any month	68
Fort Collins	5,004	May 2	May 14	Oct 7	157
Fort Collins 4 E	4,920	May 3	May 15	Oct 6	154
Fort Lewis	7,614	Jun 1	Jun 19	Sep 27	116
Fort Morgan	4,376	May 6	May 19	Oct 6	153
Fraser	8,560	Any month	Any month	Any month	32
Fruita	4,498	Apr 27	May 7	Oct 11	164
Gateway 1ENE	4,671	Apr 20	May 5	Oct 21	182
Genoa	5,593	May 8	May 22	Oct 10	155
Georgetown	8,520	May 30	Jun 14	Sep 19	112
Glade Park 17W	6,323	May 21	Jun 9	Sep 26	126
Glenwood Springs #2	5,895	May 13	May 30	Oct 3	142
Gould 4SE Sfsp	9,000	Any month	Any month	Any month	51
Grand Junction 6ESE	4,760	Apr 23	May 9	Oct 20	179
Grand Junction Walker Field	4,858	Apr 28	May 14	Oct 16	171
Grand Junction WFO	4,826	Apr 14	Apr 28	Oct 23	190
Grand Lake 1 NW	8,720	Any month	Any month	Any month	54
Grand Lake 6 SSW	8,288	Jun 13	Jun 28	Sep 7	84
Grant	8,675	Jun 15	Jun 30	Sep 9	84
Great Sand Dunes National Park & Preserve	8,183	May 21	Jun 3	Oct 1	131
Greeley Unc	4,715	May 2	May 14	Oct 8	159
Green Mount Dam	7,740	Jun 6	Jun 23	Sep 14	98
Gross Rsvr	7,970	May 24	Jun 10	Sep 23	120
Guffey 9SE	8,915	May 19	May 31	Oct 2	134
Gunnison 3SW	7,622	Any month	Any month	Any month	75
Hayden	6,467	Jun 1	Jun 16	Sep 20	109
Hermit 8 SE	8,949	Any month	Any month	Any month	62
Hohnholz Rch	7,797	Any month	Any month	Any month	56
Holly	3,401	May 1	May 14	Oct 12	163
Holyoke	3,780	May 11	May 23	Oct 3	144
Hourglass Rsvr	9,520	Any month	Any month	Any month	69
Hugo 1 NW	5,025	May 10	May 25	Oct 2	143
Idalia	3,965	May 4	May 17	Oct 9	155
Ignacio 6ESE	6,548	May 23	Jun 7	Sep 29	128
Joes	4,275	May 3	May 15	Oct 9	158
John Martin Dam	3,814	Apr 24	May 8	Oct 15	172
Julesburg	3,477	May 7	May 18	Oct 6	152
Karval	5,075	May 9	May 23	Oct 6	149
Kassler	5,587	May 8	May 22	Oct 3	147
Kim 10SSE	5,257	Apr 24	May 6	Oct 18	175
Kim 15 NNE	5,190	May 5	May 19	Oct 9	156
Kit Carson	4,302	May 10	May 24	Oct 1	142
Kit Carson 9NNE	4,346	May 7	May 24	Oct 6	151
Kremmling	7,460	Jun 14	Jun 30	Sep 5	80
La Junta	4,089	Apr 26	May 9	Oct 15	171
La Junta 17 WSW	4,386	May 8	May 25	Oct 4	148
La Junta 20 S	4,210	Apr 27	May 11	Oct 14	168
La Junta Municipal Airport	4,194	Apr 24	May 6	Oct 15	173
Lake City	8,667	Jun 8	Jun 24	Sep 17	101
Lake City 1NNE	8,714	Jun 9	Jun 22	Sep 17	99
Lake George 8 SW	8,550	Jun 2	Jun 17	Sep 19	108
Lakewood	5,640	May 3	May 18	Oct 7	155
Lamar	3,627	Apr 30	May 13	Oct 10	163
Lamar Municipal Airport	3,704	May 2	May 17	Oct 7	157
Las Animas	3,890	Apr 29	May 11	Oct 12	166
Leadville Lake County Airport	9,932	Any month	Any month	Any month	52
Lemon Dam	8,110	May 28	Jun 10	Sep 30	122
Leroy 5 WSW	4,467	May 10	May 22	Oct 6	147
Limon Wsmo	5,364	May 21	Jun 4	Sep 26	127
Lindon 5 WNW	4,851	May 15	May 30	Oct 2	139
Longmont 2 ESE	4,950	May 7	May 22	Oct 5	151
Loveland 2N	5,080	May 10	May 22	Oct 1	142
Manassa	7,695	May 28	Jun 11	Sep 21	115
Mancos 1SW	6,897	Jun 4	Jun 19	Sep 24	111
Marston Fltr Plt	5,610	May 2	May 17	Oct 11	160
Massadona 3E	6,140	May 10	May 27	Oct 4	147
Matheson 8 SE	5,830	May 12	May 26	Oct 2	141
Maybell	5,944	Jun 16	Jul 1	Sep 9	83
Meeker	6,229	Jun 4	Jun 23	Sep 16	104
Meeker Airport	6,390	May 30	Jun 13	Sep 22	117
Meredith	7,825	Any month	Any month	Any month	55
Mesa Verde National Park	7,142	May 9	May 27	Oct 14	156
Monte Vista 2W	7,695	Jun 11	Jun 25	Sep 13	92
Montrose #2	5,789	Apr 28	May 12	Oct 14	167
Montrose 11 ENE	8,402	May 20	Jun 4	Oct 1	132
Montrose Regional Airport	5,759	May 2	May 17	Oct 8	157
Monument	7,080	May 14	May 31	Oct 1	138
Monument 3S	6,821	May 17	May 30	Oct 1	136
New Raymer	4,783	May 9	May 22	Oct 4	146
New Raymer 21 N	5,180	May 18	Jun 2	Sep 29	133
Northdale	6,681	Jun 3	Jun 19	Sep 25	113
Northglenn	5,407	May 2	May 14	Oct 11	160
Norwood	7,020	May 25	Jun 13	Oct 1	128
Norwood #2	7,011	May 21	Jun 5	Oct 1	131
Nunn 7 NNE	5,390	May 13	May 27	Sep 27	136
Ordway 1 ENE	4,312	May 2	May 14	Oct 8	159
Ordway 21 N	4,767	May 3	May 16	Oct 7	155
Ouray	7,840	May 17	Jun 3	Oct 1	137
Ouray #2	7,718	May 18	May 31	Oct 4	139
Palisade	4,751	Apr 17	May 3	Oct 26	190
Paonia 1SW	5,581	May 3	May 18	Oct 12	159
Paradox 2N	5,447	May 11	May 29	Oct 5	146
Parker	5,904	May 9	May 23	Oct 3	145
Placerville	7,383	May 26	Jun 6	Sep 29	125
Pueblo Memorial Airport	4,720	Apr 30	May 12	Oct 9	161
Pueblo Rsvr	4,861	Apr 26	May 8	Oct 13	166
Ralston Rsvr	5,900	May 3	May 17	Oct 14	161
Rangely 1E	5,277	May 15	Jun 2	Oct 1	136
Ridgway	7,049	Jun 11	Jun 30	Sep 13	92
Rifle 3ENE	5,469	May 23	Jun 6	Sep 25	124
Rifle Garfield County Airport	5,530	May 11	May 27	Oct 4	143
Rio Grande Rsvr	9,492	Jun 15	Jun 30	Sep 11	85
Rocky Ford 2 SE	4,170	May 1	May 14	Oct 8	159
Roxborough State Park	6,117	May 16	Jun 1	Oct 1	136
Rush 1N	6,054	May 9	May 22	Oct 4	146
Rustic 9WSW	7,700	Jun 5	Jun 20	Sep 16	101
Ruxton Park	9,060	Jun 3	Jun 23	Sep 17	102
Rye 1SW	7,141	May 5	May 20	Oct 10	156
Saguache	7,701	May 16	May 31	Sep 28	135
Salida	7,160	May 29	Jun 12	Sep 20	112
San Luis 1 S	7,943	May 31	Jun 14	Sep 23	115
Santa Maria Rsvr	9,687	Any month	Any month	Any month	64
Sargents	8,460	Any month	Any month	Any month	33
Sedgwick 5 S	3,996	May 6	May 18	Oct 7	152
Seibert	4,706	May 4	May 17	Oct 11	158
Shaw 4ENE	5,000	May 12	May 26	Oct 4	143
Sheep Mountain	7,744	May 27	Jun 10	Sep 25	119
Sheridan Lake	4,070	Apr 27	May 10	Oct 15	170
Sheridan Lake 4E	4,039	Apr 28	May 12	Oct 13	167
Shoshone	5,992	May 1	May 14	Oct 14	164
Silverton	9,285	Any month	Any month	Any month	40
Spicer	8,385	Any month	Any month	Any month	53
Springfield Comanche	4,383	May 3	May 17	Oct 10	158
Steamboat Springs	6,866	Jun 9	Jun 24	Sep 12	93
Sterling	3,974	Apr 30	May 12	Oct 9	161
Stratton	4,399	May 6	May 17	Oct 9	155
Strontia Springs Dam	5,840	May 16	Jun 6	Sep 29	132
Sugarloaf Rsvr	9,738	Any month	Any month	Any month	53
Tacony 13 SE	4,882	May 5	May 16	Oct 6	153
Taylor Park	9,179	Jun 20	Jul 2	Sep 8	80
Telluride 4WNW	8,646	Any month	Any month	Any month	60
Trinidad	6,030	Apr 30	May 11	Oct 15	167
Trinidad Lake	6,310	May 11	May 25	Oct 4	145
Trinidad Perry Stokes Airport	5,741	May 4	May 19	Oct 9	156
Twin Lakes Rsvr	9,236	Jun 16	Jun 29	Sep 10	85
Uravan	5,021	Apr 26	May 8	Oct 18	174
Vail	8,304	Jun 21	Jul 9	Sep 7	77
Vallecito Dam	7,644	May 31	Jun 14	Sep 26	119
Vallecito Reservoir	7,673	May 18	Jun 6	Oct 11	145
Virginia Dale 7 ENE	7,015	May 31	Jun 15	Sep 19	110
Walden	8,056	Any month	Any month	Any month	31
Walsenburg 1 NW	6,292	May 6	May 20	Oct 4	149
Walsh 1 W	3,978	Apr 30	May 12	Oct 14	166
Waterdale	5,230	May 12	May 30	Oct 1	141
Waverly 1W	7,603	Jun 6	Jun 22	Sep 15	100
Westcliffe	7,873	Jun 11	Jun 28	Sep 9	89
WFO Pueblo	4,653	Apr 30	May 12	Oct 9	162
Wheat Ridge 2	5,398	May 5	May 18	Oct 5	151
Wild Horse 6N	4,654	May 4	May 17	Oct 8	155
Williams Fork Dam	7,618	Jun 12	Jun 25	Sep 10	89
Woodrow 6NNE	4,374	May 15	May 28	Oct 1	140
Wray	3,553	May 7	May 19	Oct 6	151
Yampa	7,857	Jun 14	Jun 28	Sep 11	89
Yellow Jacket 2W	6,933	May 17	Jun 4	Oct 9	145
Yellow Jacket 4NE	7,090	May 15	May 31	Oct 8	147
Yuma	4,134	May 1	May 13	Oct 12	164

Frequently asked questions

When is the last frost in Colorado?

The median last spring frost (32°F) across Colorado's NOAA weather stations is May 11, based on 1991–2020 climate normals. It ranges from April 14 at Grand Junction WFO to June 21 at Vail. For a safer planting date, use the 10%-risk date; the state median for that is May 27.

When is the first frost in Colorado?

The median first fall frost across Colorado's stations is October 4. The earliest median first frost is September 2 at Boulder 14 W, and the latest is October 26 at Palisade.

How long is the growing season in Colorado?

The median frost-free season is 145 days across Colorado's stations, from 71 days at Boulder 14 W to 190 days at Palisade.

When should I plant tomatoes in Colorado?

Plant tomatoes outdoors after your local last frost, ideally after the 10%-risk date when nights stay above 50°F. At a typical Colorado station that means starting seeds indoors 6–8 weeks before May 11 and transplanting from about May 27. Check your ZIP code, because dates vary by weeks across the state.

Can it frost in summer in Colorado?

Yes, at 24 stations in Colorado a 32°F night is possible in any month, mostly at high elevation or far north. There is no reliable frost-free season there; use cold-hardy crops and row covers.

How to use these dates

Frost dates are 30-year averages from NOAA, not forecasts. Use them to plan seed starting and planting, then watch the 10-day forecast as the date approaches. Cold air settles in valleys and low spots, so a garden at the bottom of a slope can frost a week or more later in spring than the nearest station shows.

Ready to plan? The planting calendar by ZIP code turns these dates into start-indoors, transplant and sowing dates for 30 crops.

Sources and method

Dates are the 32°F freeze probabilities published in the NOAA NCEI 1991–2020 U.S. Climate Normals for each station. Station names are NOAA's, lightly expanded for readability. See the methodology or download the full table.