Frost dates for South Phoenix, AZ
At South Phoenix, the median last spring frost (32°F) is Jan 21 and the median first fall frost is Dec 16, for a typical growing season of 331 days. For a 90% chance that the last frost has passed, wait until Feb 20. Nearby ZIP codes are in USDA hardiness zones 9b to 10a.
- Jan 21Last spring frost (median)50% chance of 32°F after this date
- Feb 20Safer planting date10% chance of 32°F after this date
- Dec 16First fall frost (median)50% chance of 32°F by this date
- 331 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 | Jan 16 | Feb 15 | Mar 7 |
| 32°F | Dec 24 | Jan 21 | Feb 20 |
| 28°F | Dec 13 | Jan 3 | Feb 8 |
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 | Nov 16 | Dec 1 | Dec 17 |
| 32°F | Nov 29 | Dec 16 | Jan 9 |
| 28°F | Dec 10 | Dec 29 | Jan 28 |
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 | 263 days | 289 days | 322 days |
| 32°F | 295 days | 331 days | 358 days |
| 28°F | 334 days | 365 days | 365 days |
| 24°F | 365 days | 365 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 94% |
| 28°F | 47% |
| 24°F | 4% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 85042 | 10a | 30 to 35°F | 3 km |
| 85041 | 10a | 30 to 35°F | 4 km |
| 85007 | 10a | 30 to 35°F | 7 km |
| 85044 | 10a | 30 to 35°F | 8 km |
| 85009 | 10a | 30 to 35°F | 9 km |
| 85048 | 9b | 25 to 30°F | 10 km |
| 85035 | 9b | 25 to 30°F | 15 km |
| 85031 | 9b | 25 to 30°F | 15 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 USC00028112, at 33.3814, -112.0700, elevation 352 m (1,155 ft).
- Data quality: Representative (10+ years), 17 years of freeze data.
- Average days per year at or below 32°F: 8.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Phoenix Sky Harbor Intl Airport (8 km)
- Laveen 3 SSE (9 km)
- Tempe Asu (15 km)
- Maricopa 4 N (30 km)
- Litchfield Park (30 km)
- Scottsdale Muni Airport (31 km)
- Youngtown (32 km)
- Phoenix Deer Valley Muni Airport (34 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.