Frost dates for San Simon, AZ
At San Simon, the median last spring frost (32°F) is Apr 16 and the median first fall frost is Nov 2, for a typical growing season of 198 days. For a 90% chance that the last frost has passed, wait until May 4. Nearby ZIP codes are in USDA hardiness zones 8a to 8b.
- Apr 16Last spring frost (median)50% chance of 32°F after this date
- May 4Safer planting date10% chance of 32°F after this date
- Nov 2First fall frost (median)50% chance of 32°F by this date
- 198 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 14 | May 1 | May 17 |
| 32°F | Mar 31 | Apr 16 | May 4 |
| 28°F | Mar 6 | Apr 2 | Apr 20 |
| 24°F | Feb 7 | Mar 7 | Apr 5 |
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 8 | Oct 22 | Nov 5 |
| 32°F | Oct 17 | Nov 2 | Nov 16 |
| 28°F | Oct 27 | Nov 12 | Nov 26 |
| 24°F | Nov 6 | Nov 24 | Dec 9 |
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 | 152 days | 174 days | 195 days |
| 32°F | 175 days | 198 days | 220 days |
| 28°F | 197 days | 224 days | 253 days |
| 24°F | 226 days | 256 days | 288 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
Closest ZIP codes (each is closer to another station)
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 85605 | 8b | 15 to 20°F | 23 km |
| 85632 | 8a | 10 to 15°F | 26 km |
| 85534 | 8a | 10 to 15°F | 48 km |
| 88045 | 8a | 10 to 15°F | 50 km |
| 88056 | 8a | 10 to 15°F | 55 km |
| 85546 | 8b | 15 to 20°F | 57 km |
| 85551 | 8b | 15 to 20°F | 59 km |
| 85625 | 8a | 10 to 15°F | 62 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 USC00027560, at 32.2933, -109.2269, elevation 1091 m (3,580 ft).
- Data quality: Standard (24+ years of data), 26 years of freeze data.
- Average days per year at or below 32°F: 91.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Bowie (25 km)
- Chiricahua National Monument (34 km)
- Paradise (40 km)
- Portal 4 SW (46 km)
- Duncan (52 km)
- Willcox (58 km)
- Pearce - Sunsites (70 km)
- Safford Ag Center (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.