Frost dates for Denver-Stapleton, CO
At Denver-Stapleton, the median last spring frost (32°F) is May 4 and the median first fall frost is Oct 8, for a typical growing season of 156 days. For a 90% chance that the last frost has passed, wait until May 16. Nearby ZIP codes are in USDA hardiness zone 6a.
- May 4Last spring frost (median)50% chance of 32°F after this date
- May 16Safer planting date10% chance of 32°F after this date
- Oct 8First fall frost (median)50% chance of 32°F by this date
- 156 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 12 | May 26 |
| 32°F | Apr 20 | May 4 | May 16 |
| 28°F | Apr 6 | Apr 22 | May 7 |
| 24°F | Mar 23 | Apr 10 | Apr 27 |
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 16 | Oct 1 | Oct 13 |
| 32°F | Sep 25 | Oct 8 | Oct 20 |
| 28°F | Oct 3 | Oct 18 | Oct 31 |
| 24°F | Oct 12 | Oct 27 | Nov 12 |
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 | 121 days | 140 days | 156 days |
| 32°F | 138 days | 156 days | 175 days |
| 28°F | 158 days | 177 days | 198 days |
| 24°F | 176 days | 200 days | 223 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 |
|---|---|---|---|
| 80238 | 6a | -10 to -5°F | 2 km |
| 80010 | 6a | -10 to -5°F | 3 km |
| 80045 | 6a | -10 to -5°F | 3 km |
| 80266 | 6a | -10 to -5°F | 4 km |
| 80207 | 6a | -10 to -5°F | 4 km |
| 80239 | 6a | -10 to -5°F | 4 km |
| 80230 | 6a | -10 to -5°F | 5 km |
| 80220 | 6a | -10 to -5°F | 5 km |
| 80011 | 6a | -10 to -5°F | 7 km |
| 80247 | 6a | -10 to -5°F | 7 km |
| 80012 | 6a | -10 to -5°F | 8 km |
| 80224 | 6a | -10 to -5°F | 9 km |
| 80024 | 6a | -10 to -5°F | 10 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 USW00023062, at 39.7633, -104.8694, elevation 1611 m (5,286 ft).
- Data quality: Standard (24+ years of data), 28 years of freeze data.
- Average days per year at or below 32°F: 156.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Denver Water Dept (12 km)
- Cherry Creek Dam (16 km)
- Northglenn (19 km)
- Denver Intl Airport (20 km)
- Brighton 3 SE (20 km)
- Wheat Ridge 2 (21 km)
- Denver Centennial Airport (22 km)
- Lakewood (22 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.