Frost dates for Willcox, AZ
At Willcox, the median last spring frost (32°F) is Apr 9 and the median first fall frost is Oct 31, for a typical growing season of 204 days. For a 90% chance that the last frost has passed, wait until Apr 29. Nearby ZIP codes are in USDA hardiness zone 8b.
- Apr 9Last spring frost (median)50% chance of 32°F after this date
- Apr 29Safer planting date10% chance of 32°F after this date
- Oct 31First fall frost (median)50% chance of 32°F by this date
- 204 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 9 | Apr 26 | May 10 |
| 32°F | Mar 20 | Apr 9 | Apr 29 |
| 28°F | Feb 24 | Mar 16 | Apr 10 |
| 24°F | Jan 30 | Feb 24 | Mar 13 |
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 11 | Oct 22 | Nov 3 |
| 32°F | Oct 20 | Oct 31 | Nov 14 |
| 28°F | Oct 28 | Nov 12 | Nov 26 |
| 24°F | Nov 8 | Nov 25 | Dec 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 | 159 days | 178 days | 198 days |
| 32°F | 181 days | 204 days | 225 days |
| 28°F | 209 days | 237 days | 264 days |
| 24°F | 246 days | 274 days | 303 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 |
|---|---|---|---|
| 85643 | 8b | 15 to 20°F | 28 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 USC00029334, at 32.2553, -109.8369, elevation 1271 m (4,170 ft).
- Data quality: Representative (10+ years), 24 years of freeze data.
- Average days per year at or below 32°F: 93.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Bowie (33 km)
- Pearce - Sunsites (36 km)
- Cascabel (48 km)
- Chiricahua National Monument (53 km)
- Benson 6se (56 km)
- San Simon (58 km)
- Safford Ag Center (64 km)
- Tombstone (64 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.