Frost dates for Kartchner Caverns, AZ
At Kartchner Caverns, the median last spring frost (32°F) is Mar 20 and the median first fall frost is Nov 15, for a typical growing season of 237 days. For a 90% chance that the last frost has passed, wait until Apr 11. Nearby ZIP codes are in USDA hardiness zones 8a to 9a.
- Mar 20Last spring frost (median)50% chance of 32°F after this date
- Apr 11Safer planting date10% chance of 32°F after this date
- Nov 15First fall frost (median)50% chance of 32°F by this date
- 237 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 21 | Apr 10 | Apr 28 |
| 32°F | Feb 25 | Mar 20 | Apr 11 |
| 28°F | Jan 31 | Feb 28 | Mar 21 |
| 24°F | Jan 5 | Feb 6 | 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 22 | Nov 4 | Nov 18 |
| 32°F | Nov 1 | Nov 15 | Dec 2 |
| 28°F | Nov 10 | Nov 28 | Dec 19 |
| 24°F | Nov 23 | Dec 17 | Jan 19 |
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 | 184 days | 207 days | 230 days |
| 32°F | 209 days | 237 days | 265 days |
| 28°F | 241 days | 271 days | 305 days |
| 24°F | 277 days | 313 days | 350 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 98% |
Closest ZIP codes (each is closer to another station)
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 85616 | 8b | 15 to 20°F | 15 km |
| 85630 | 8b | 15 to 20°F | 18 km |
| 85627 | 8b | 15 to 20°F | 22 km |
| 85611 | 8a | 10 to 15°F | 26 km |
| 85638 | 8b | 15 to 20°F | 34 km |
| 85613 | 8b | 15 to 20°F | 34 km |
| 85637 | 8a | 10 to 15°F | 34 km |
| 85641 | 9a | 20 to 25°F | 34 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 USC00024534, at 31.8353, -110.3553, elevation 1430 m (4,690 ft).
- Data quality: Representative (10+ years), 11 years of freeze data.
- Average days per year at or below 32°F: 40.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Benson 6se (12 km)
- Fort Huachuca Pioneer Airfield (26 km)
- Tombstone (30 km)
- Elgin 5 S (31 km)
- Sonoita (33 km)
- Sierra Vista (34 km)
- Canelo 1 NW (35 km)
- Santa Rita Exp. Range (47 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.