Frost dates for Burlington Carson Airport, CO
At Burlington Carson Airport, the median last spring frost (32°F) is May 2 and the median first fall frost is Oct 10, for a typical growing season of 160 days. For a 90% chance that the last frost has passed, wait until May 16. Nearby ZIP codes are in USDA hardiness zone 6a.
- May 2Last spring frost (median)50% chance of 32°F after this date
- May 16Safer planting date10% chance of 32°F after this date
- Oct 10First fall frost (median)50% chance of 32°F by this date
- 160 daysGrowing season (median)between 32°F freezes
Last spring frost dates
The chance that the temperature drops to the threshold after each date.
| Temperature | 90% chance later | 50% chance later | 10% chance later |
|---|---|---|---|
| 36°F | May 1 | May 13 | May 27 |
| 32°F | Apr 19 | May 2 | May 16 |
| 28°F | Apr 6 | Apr 23 | May 6 |
| 24°F | Mar 26 | Apr 11 | Apr 24 |
First fall frost dates
The chance that the temperature has dropped to the threshold by each date.
| Temperature | 10% chance by | 50% chance by | 90% chance by |
|---|---|---|---|
| 36°F | Sep 17 | Oct 1 | Oct 13 |
| 32°F | Sep 27 | Oct 10 | Oct 22 |
| 28°F | Oct 6 | Oct 19 | Oct 30 |
| 24°F | Oct 14 | Oct 28 | Nov 9 |
Growing season length
Days between the last spring and first fall freeze, as the length reached in 9, 5 and 1 out of 10 years.
| Temperature | 9 in 10 years at least | 5 in 10 years at least | 1 in 10 years at least |
|---|---|---|---|
| 36°F | 122 days | 140 days | 157 days |
| 32°F | 141 days | 160 days | 177 days |
| 28°F | 160 days | 179 days | 198 days |
| 24°F | 179 days | 198 days | 220 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
Closest ZIP codes (each is closer to another station)
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 80807 | 6a | -10 to -5°F | 10 km |
| 80805 | 6a | -10 to -5°F | 14 km |
| 80836 | 6a | -10 to -5°F | 26 km |
| 67741 | 6a | -10 to -5°F | 29 km |
| 80861 | 6a | -10 to -5°F | 43 km |
| 67735 | 6a | -10 to -5°F | 45 km |
| 80802 | 6a | -10 to -5°F | 48 km |
| 80810 | 6a | -10 to -5°F | 49 km |
Not the official USDA Plant Hardiness Zone Map. Zones shown here are the values published in the USDA-ARS / Oregon State University PRISM Group 2023 ZIP code tables, shown unaltered. For the official interactive map, visit planthardiness.ars.usda.gov.
About this station
- NOAA station ID USW00003026, at 39.2447, -102.2842, elevation 1278 m (4,192 ft).
- Data quality: Representative (10+ years), 21 years of freeze data.
- Average days per year at or below 32°F: 162.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Burlington (7 km)
- Arapahoe 14n (25 km)
- Stratton (28 km)
- Cheyenne Wells 2ne (43 km)
- Bonny Dam 2ne (48 km)
- Seibert (51 km)
- Idalia (51 km)
- Kit Carson 9nne (55 km)
Sources
- NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020, annual/seasonal normals by station (version 1.0.1), file dated June 27, 2023; documentation.
- USDA Agricultural Research Service and PRISM Group, Oregon State University, 2023 Plant Hardiness Zone Map ZIP code tables (CONUS, Alaska, Hawaii, Puerto Rico), files dated November 17, 2023. Data © PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed November 1, 2026. Official map: planthardiness.ars.usda.gov.
- U.S. Census Bureau, 2024 Gazetteer ZIP Code Tabulation Areas file, dated August 30, 2024 (ZIP centroids used to find the nearest station).
Freeze dates are 30-year probabilities, not forecasts. Check your local forecast before planting tender plants.