Frost dates for Colorado City, AZ
At Colorado City, the median last spring frost (32°F) is Apr 26 and the median first fall frost is Oct 25, for a typical growing season of 180 days. For a 90% chance that the last frost has passed, wait until May 15. Nearby ZIP codes are in USDA hardiness zones 7a to 7b.
- Apr 26Last spring frost (median)50% chance of 32°F after this date
- May 15Safer planting date10% chance of 32°F after this date
- Oct 25First fall frost (median)50% chance of 32°F by this date
- 180 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 23 | May 8 | May 31 |
| 32°F | Apr 6 | Apr 26 | May 15 |
| 28°F | Mar 17 | Apr 10 | May 2 |
| 24°F | Feb 22 | Mar 17 | Apr 12 |
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 | Oct 1 | Oct 15 | Oct 29 |
| 32°F | Oct 11 | Oct 25 | Nov 9 |
| 28°F | Oct 19 | Nov 5 | Nov 19 |
| 24°F | Oct 29 | Nov 15 | Nov 29 |
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 | 134 days | 157 days | 180 days |
| 32°F | 157 days | 180 days | 205 days |
| 28°F | 180 days | 206 days | 234 days |
| 24°F | 210 days | 241 days | 269 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 |
|---|---|---|---|
| 84784 | 7a | 0 to 5°F | 3 km |
| 86021 | 7b | 5 to 10°F | 17 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 USC00021920, at 36.9936, -112.9719, elevation 1524 m (5,001 ft).
- Data quality: Representative (10+ years), 21 years of freeze data.
- Average days per year at or below 32°F: 120.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Pipe Spring National Monument (25 km)
- Beaver Dam (87 km)
- Bright Angel Ranger Station (119 km)
- Lees Ferry (123 km)
- Phantom Rch (126 km)
- Grand Canyon National Park 2 (128 km)
- Grand Canyon Visitor Center (129 km)
- Wahweap (131 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.