Frost dates for Ouray #2, CO
At Ouray #2, the median last spring frost (32°F) is May 18 and the median first fall frost is Oct 4, for a typical growing season of 139 days. For a 90% chance that the last frost has passed, wait until May 31. Nearby ZIP codes are in USDA hardiness zones 5a to 6a.
- May 18Last spring frost (median)50% chance of 32°F after this date
- May 31Safer planting date10% chance of 32°F after this date
- Oct 4First fall frost (median)50% chance of 32°F by this date
- 139 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 17 | May 30 | Jun 11 |
| 32°F | May 4 | May 18 | May 31 |
| 28°F | Apr 21 | May 4 | May 21 |
| 24°F | Apr 7 | Apr 23 | May 7 |
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 14 | Sep 26 | Oct 6 |
| 32°F | Sep 24 | Oct 4 | Oct 17 |
| 28°F | Oct 1 | Oct 13 | Oct 27 |
| 24°F | Oct 10 | Oct 24 | Nov 7 |
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 | 100 days | 118 days | 134 days |
| 32°F | 121 days | 139 days | 157 days |
| 28°F | 141 days | 160 days | 180 days |
| 24°F | 163 days | 184 days | 205 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 |
|---|---|---|---|
| 81427 | 5b | -15 to -10°F | 5 km |
| 81432 | 6a | -10 to -5°F | 13 km |
| 81426 | 5b | -15 to -10°F | 22 km |
| 81235 | 5a | -20 to -15°F | 24 km |
| 81435 | 5b | -15 to -10°F | 28 km |
| 81220 | 5b | -15 to -10°F | 35 km |
| 81430 | 5b | -15 to -10°F | 35 km |
| 81433 | 5a | -20 to -15°F | 35 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 USC00056205, at 38.0264, -107.6725, elevation 2352 m (7,718 ft).
- Data quality: Representative (10+ years), 13 years of freeze data.
- Average days per year at or below 32°F: 179.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Ouray (1 km)
- Ridgway (16 km)
- Telluride 4wnw (20 km)
- Silverton (24 km)
- Lake City (31 km)
- Lake City 1nne (32 km)
- Placerville (33 km)
- Cimarron (47 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.