Frost dates for Collbran 1wsw, CO
At Collbran 1wsw, the median last spring frost (32°F) is May 17 and the median first fall frost is Sep 30, for a typical growing season of 136 days. For a 90% chance that the last frost has passed, wait until Jun 3. Nearby ZIP codes are in USDA hardiness zones 5b to 7a.
- May 17Last spring frost (median)50% chance of 32°F after this date
- Jun 3Safer planting date10% chance of 32°F after this date
- Sep 30First fall frost (median)50% chance of 32°F by this date
- 136 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 31 | Jun 13 |
| 32°F | May 2 | May 17 | Jun 3 |
| 28°F | Apr 19 | May 3 | May 20 |
| 24°F | Apr 6 | Apr 23 | May 8 |
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 10 | Sep 22 | Oct 2 |
| 32°F | Sep 18 | Sep 30 | Oct 12 |
| 28°F | Sep 27 | Oct 9 | Oct 21 |
| 24°F | Oct 4 | Oct 18 | Nov 2 |
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 | 96 days | 113 days | 131 days |
| 32°F | 114 days | 136 days | 155 days |
| 28°F | 138 days | 159 days | 177 days |
| 24°F | 158 days | 178 days | 200 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 |
|---|---|---|---|
| 81646 | 5b | -15 to -10°F | 15 km |
| 81643 | 6b | -5 to 0°F | 19 km |
| 81624 | 6a | -10 to -5°F | 22 km |
| 81413 | 5b | -15 to -10°F | 30 km |
| 81635 | 6a | -10 to -5°F | 34 km |
| 81526 | 7a | 0 to 5°F | 36 km |
| 81652 | 6a | -10 to -5°F | 37 km |
| 81418 | 6b | -5 to 0°F | 38 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 USC00051743, at 39.2367, -107.9797, elevation 1832 m (6,009 ft).
- Data quality: Representative (10+ years), 18 years of freeze data.
- Average days per year at or below 32°F: 182.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Bonham Rsvr (16 km)
- Palisade (35 km)
- Cedaredge 3e (38 km)
- Rifle Garfield Co Airport (39 km)
- Rifle 3ene (42 km)
- Altenbern (45 km)
- Grand Junction 6ese (47 km)
- Grand Junction WFO (49 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.