Frost dates for Cortez Montezuma Co Airport, CO
At Cortez Montezuma Co Airport, the median last spring frost (32°F) is May 27 and the median first fall frost is Sep 28, for a typical growing season of 125 days. For a 90% chance that the last frost has passed, wait until Jun 11. Nearby ZIP codes are in USDA hardiness zone 7a.
- May 27Last spring frost (median)50% chance of 32°F after this date
- Jun 11Safer planting date10% chance of 32°F after this date
- Sep 28First fall frost (median)50% chance of 32°F by this date
- 125 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 26 | Jun 9 | Jun 24 |
| 32°F | May 9 | May 27 | Jun 11 |
| 28°F | Apr 25 | May 8 | May 31 |
| 24°F | Apr 9 | Apr 25 | May 10 |
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 8 | Sep 20 | Sep 30 |
| 32°F | Sep 17 | Sep 28 | Oct 10 |
| 28°F | Sep 26 | Oct 7 | Oct 21 |
| 24°F | Oct 4 | Oct 17 | Nov 1 |
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 | 82 days | 100 days | 119 days |
| 32°F | 104 days | 125 days | 145 days |
| 28°F | 127 days | 150 days | 169 days |
| 24°F | 153 days | 174 days | 195 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 81321 | 7a | 0 to 5°F | 10 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 USW00093069, at 37.3031, -108.6275, elevation 1803 m (5,914 ft).
- Data quality: Representative (10+ years), 24 years of freeze data.
- Average days per year at or below 32°F: 191.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Cortez (5 km)
- Cortez 8 SE (12 km)
- Mesa Verde National Park (17 km)
- Yellow Jacket 2w (27 km)
- Mancos 1sw (28 km)
- Yellow Jacket 4ne (29 km)
- Fort Lewis (52 km)
- Dove Creek (57 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.