Frost dates for Sterling, CO
At Sterling, the median last spring frost (32°F) is Apr 30 and the median first fall frost is Oct 9, for a typical growing season of 161 days. For a 90% chance that the last frost has passed, wait until May 12. Nearby ZIP codes are in USDA hardiness zone 5b.
- Apr 30Last spring frost (median)50% chance of 32°F after this date
- May 12Safer planting date10% chance of 32°F after this date
- Oct 9First fall frost (median)50% chance of 32°F by this date
- 161 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 11 | May 24 |
| 32°F | Apr 16 | Apr 30 | May 12 |
| 28°F | Apr 4 | Apr 18 | May 3 |
| 24°F | Mar 21 | Apr 6 | Apr 21 |
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 11 |
| 32°F | Sep 28 | Oct 9 | Oct 20 |
| 28°F | Oct 6 | Oct 18 | Oct 29 |
| 24°F | Oct 15 | 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 | 125 days | 142 days | 158 days |
| 32°F | 143 days | 161 days | 178 days |
| 28°F | 163 days | 180 days | 197 days |
| 24°F | 183 days | 202 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 |
|---|---|---|---|
| 80751 | 5b | -15 to -10°F | 4 km |
| 80722 | 5b | -15 to -10°F | 17 km |
| 80741 | 5b | -15 to -10°F | 24 km |
| 80745 | 5b | -15 to -10°F | 34 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 USC00057950, at 40.6278, -103.2083, elevation 1211 m (3,974 ft).
- Data quality: Representative (10+ years), 13 years of freeze data.
- Average days per year at or below 32°F: 164.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Leroy 5 WSW (22 km)
- Fleming 3sw (30 km)
- Crook (43 km)
- Akron Washington Co Airport (51 km)
- Akron 4 E (53 km)
- New Raymer (54 km)
- Sedgwick 5 S (64 km)
- New Raymer 21 N (65 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.