Frost dates for Lamar, CO
At Lamar, the median last spring frost (32°F) is Apr 30 and the median first fall frost is Oct 10, for a typical growing season of 163 days. For a 90% chance that the last frost has passed, wait until May 13. Nearby ZIP codes are in USDA hardiness zone 6a.
- Apr 30Last spring frost (median)50% chance of 32°F after this date
- May 13Safer planting date10% chance of 32°F after this date
- Oct 10First 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 29 | May 10 | May 23 |
| 32°F | Apr 17 | Apr 30 | May 13 |
| 28°F | Apr 5 | Apr 18 | May 2 |
| 24°F | Mar 22 | Apr 6 | Apr 20 |
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 4 | Oct 14 |
| 32°F | Oct 1 | Oct 10 | Oct 21 |
| 28°F | Oct 7 | Oct 20 | Oct 30 |
| 24°F | Oct 17 | Oct 29 | Nov 9 |
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 | 129 days | 145 days | 162 days |
| 32°F | 145 days | 163 days | 181 days |
| 28°F | 164 days | 183 days | 201 days |
| 24°F | 186 days | 204 days | 224 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 |
|---|---|---|---|
| 81052 | 6a | -10 to -5°F | 13 km |
| 81057 | 6a | -10 to -5°F | 24 km |
| 81092 | 6a | -10 to -5°F | 28 km |
| 81041 | 6a | -10 to -5°F | 34 km |
| 81043 | 6a | -10 to -5°F | 36 km |
| 81044 | 6a | -10 to -5°F | 38 km |
| 81036 | 6a | -10 to -5°F | 38 km |
| 81047 | 6a | -10 to -5°F | 40 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 USC00054770, at 38.0936, -102.6306, elevation 1106 m (3,627 ft).
- Data quality: Standard (24+ years of data), 28 years of freeze data.
- Average days per year at or below 32°F: 160.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Lamar Muni Airport (6 km)
- John Martin Dam (26 km)
- Holly (44 km)
- Eads (44 km)
- Sheridan Lake (51 km)
- Las Animas (51 km)
- Sheridan Lake 4e (55 km)
- Kit Carson (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.