Frost dates for Bonny Dam 2ne, CO
At Bonny Dam 2ne, the median last spring frost (32°F) is May 5 and the median first fall frost is Oct 10, for a typical growing season of 155 days. For a 90% chance that the last frost has passed, wait until May 19. Nearby ZIP codes are in USDA hardiness zones 5b to 6a.
- May 5Last spring frost (median)50% chance of 32°F after this date
- May 19Safer planting date10% chance of 32°F after this date
- Oct 10First fall frost (median)50% chance of 32°F by this date
- 155 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 2 | May 15 | May 26 |
| 32°F | Apr 21 | May 5 | May 19 |
| 28°F | Apr 9 | Apr 25 | May 9 |
| 24°F | Mar 28 | Apr 13 | Apr 29 |
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 18 | Oct 1 | Oct 12 |
| 32°F | Sep 28 | Oct 10 | Oct 21 |
| 28°F | Oct 6 | Oct 18 | Oct 28 |
| 24°F | Oct 14 | Oct 26 | Nov 8 |
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 | 118 days | 137 days | 154 days |
| 32°F | 137 days | 155 days | 173 days |
| 28°F | 156 days | 173 days | 193 days |
| 24°F | 174 days | 194 days | 215 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 |
|---|---|---|---|
| 80735 | 6a | -10 to -5°F | 12 km |
| 67756 | 6a | -10 to -5°F | 29 km |
| 67741 | 6a | -10 to -5°F | 32 km |
| 80824 | 5b | -15 to -10°F | 33 km |
| 80755 | 5b | -15 to -10°F | 33 km |
| 80807 | 6a | -10 to -5°F | 38 km |
| 67735 | 6a | -10 to -5°F | 45 km |
| 80822 | 5b | -15 to -10°F | 48 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 USC00050834, at 39.6567, -102.1192, elevation 1133 m (3,717 ft).
- Data quality: Standard (24+ years of data), 25 years of freeze data.
- Average days per year at or below 32°F: 154.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Idalia (16 km)
- Burlington (41 km)
- Wray (48 km)
- Burlington Carson Airport (48 km)
- Joes (48 km)
- Stratton (57 km)
- Arapahoe 14n (69 km)
- Yuma (73 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.