Frost dates for Douglas, AZ
At Douglas, the median last spring frost (32°F) is Mar 18 and the median first fall frost is Nov 13, for a typical growing season of 235 days. For a 90% chance that the last frost has passed, wait until Apr 12. Nearby ZIP codes are in USDA hardiness zone 8a.
- Mar 18Last spring frost (median)50% chance of 32°F after this date
- Apr 12Safer planting date10% chance of 32°F after this date
- Nov 13First fall frost (median)50% chance of 32°F by this date
- 235 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 | Mar 18 | Apr 7 | Apr 27 |
| 32°F | Feb 27 | Mar 18 | Apr 12 |
| 28°F | Jan 31 | Feb 27 | Mar 24 |
| 24°F | Jan 5 | Feb 3 | Mar 3 |
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 20 | Nov 3 | Nov 19 |
| 32°F | Oct 27 | Nov 13 | Nov 30 |
| 28°F | Nov 5 | Nov 25 | Dec 9 |
| 24°F | Nov 15 | Dec 6 | Dec 23 |
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 | 183 days | 207 days | 230 days |
| 32°F | 204 days | 235 days | 264 days |
| 28°F | 235 days | 268 days | 300 days |
| 24°F | 270 days | 303 days | 336 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 |
|---|---|---|---|
| 85626 | 8a | 10 to 15°F | 3 km |
| 85607 | 8a | 10 to 15°F | 25 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 USC00022659, at 31.3450, -109.5394, elevation 1231 m (4,040 ft).
- Data quality: Representative (10+ years), 17 years of freeze data.
- Average days per year at or below 32°F: 60.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Douglas Bisbee Inl Airport (14 km)
- Mc Neal (31 km)
- Bisbee 1wnw (39 km)
- Tombstone (65 km)
- Portal 4 SW (68 km)
- Coronado Nmem (68 km)
- Pearce - Sunsites (71 km)
- Paradise (72 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.