Frost dates for Organ Pipe Cactus National Monument, AZ
At Organ Pipe Cactus National Monument, the median last spring frost (32°F) is Feb 4 and the median first fall frost is Dec 15, for a typical growing season of 314 days. For a 90% chance that the last frost has passed, wait until Mar 3. Nearby ZIP codes are in USDA hardiness zone 9b.
- Feb 4Last spring frost (median)50% chance of 32°F after this date
- Mar 3Safer planting date10% chance of 32°F after this date
- Dec 15First fall frost (median)50% chance of 32°F by this date
- 314 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 31 | Feb 28 | Mar 27 |
| 32°F | Dec 31 | Feb 4 | Mar 3 |
| 28°F | Dec 22 | Jan 18 | Feb 23 |
| 24°F | Jan 3 | Jan 27 | Mar 24 |
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 11 | Dec 1 | Dec 17 |
| 32°F | Nov 26 | Dec 15 | Jan 9 |
| 28°F | Dec 8 | Jan 5 | Feb 9 |
| 24°F | Jan 3 | Jan 27 | Mar 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 | 240 days | 273 days | 305 days |
| 32°F | 279 days | 314 days | 351 days |
| 28°F | 317 days | 361 days | 365 days |
| 24°F | 361 days | 365 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 96% |
| 28°F | 56% |
| 24°F | 10% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 85341 | 9b | 25 to 30°F | 8 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 USC00026132, at 31.9556, -112.8003, elevation 512 m (1,678 ft).
- Data quality: Representative (10+ years), 24 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
- Ajo (46 km)
- Gila Bend 2se (110 km)
- Kitt Peak (113 km)
- Painted Rock Dam (127 km)
- Sasabe (130 km)
- Dateland Whitewing Rch (131 km)
- Anvil Rch (134 km)
- Arizona City (135 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.