Frost dates for Holly, CO
At Holly, the median last spring frost (32°F) is May 1 and the median first fall frost is Oct 12, for a typical growing season of 163 days. For a 90% chance that the last frost has passed, wait until May 14. Nearby ZIP codes are in USDA hardiness zone 6a.
- May 1Last spring frost (median)50% chance of 32°F after this date
- May 14Safer planting date10% chance of 32°F after this date
- Oct 12First fall frost (median)50% chance of 32°F by this date
- 163 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 | Apr 30 | May 10 | May 25 |
| 32°F | Apr 18 | May 1 | May 14 |
| 28°F | Apr 7 | Apr 21 | May 4 |
| 24°F | Mar 25 | Apr 10 | Apr 25 |
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 23 | Oct 3 | Oct 15 |
| 32°F | Sep 29 | Oct 12 | Oct 23 |
| 28°F | Oct 7 | Oct 21 | Nov 2 |
| 24°F | Oct 18 | Oct 30 | Nov 11 |
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 | 126 days | 145 days | 161 days |
| 32°F | 144 days | 163 days | 179 days |
| 28°F | 162 days | 181 days | 199 days |
| 24°F | 182 days | 201 days | 221 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 |
|---|---|---|---|
| 81047 | 6a | -10 to -5°F | 7 km |
| 81043 | 6a | -10 to -5°F | 11 km |
| 67836 | 6a | -10 to -5°F | 12 km |
| 81041 | 6a | -10 to -5°F | 32 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 USC00054076, at 38.0517, -102.1317, elevation 1037 m (3,401 ft).
- Data quality: Representative (10+ years), 20 years of freeze data.
- Average days per year at or below 32°F: 161.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Lamar (44 km)
- Sheridan Lake 4e (47 km)
- Sheridan Lake (49 km)
- Lamar Muni Airport (49 km)
- John Martin Dam (70 km)
- Arapahoe 12s (70 km)
- Eads (73 km)
- Walsh 1 W (76 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.