Frost dates for San Carlos Reservoir, AZ
At San Carlos Reservoir, the median last spring frost (32°F) is Mar 13 and the median first fall frost is Nov 19, for a typical growing season of 247 days. For a 90% chance that the last frost has passed, wait until Apr 6. Nearby ZIP codes are in USDA hardiness zones 8b to 9a.
- Mar 13Last spring frost (median)50% chance of 32°F after this date
- Apr 6Safer planting date10% chance of 32°F after this date
- Nov 19First fall frost (median)50% chance of 32°F by this date
- 247 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 11 | Apr 1 | Apr 21 |
| 32°F | Feb 17 | Mar 13 | Apr 6 |
| 28°F | Jan 21 | Feb 17 | Mar 13 |
| 24°F | Dec 24 | Jan 25 | Feb 25 |
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 24 | Nov 9 | Nov 23 |
| 32°F | Nov 3 | Nov 19 | Dec 4 |
| 28°F | Nov 14 | Dec 1 | Dec 18 |
| 24°F | Nov 25 | Dec 13 | Jan 14 |
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 | 197 days | 219 days | 244 days |
| 32°F | 219 days | 247 days | 276 days |
| 28°F | 249 days | 284 days | 317 days |
| 24°F | 289 days | 326 days | 360 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 93% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 85542 | 9a | 20 to 25°F | 26 km |
| 85530 | 8b | 15 to 20°F | 26 km |
| 85192 | 9a | 20 to 25°F | 28 km |
| 85135 | 9a | 20 to 25°F | 31 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 USC00027480, at 33.1819, -110.5261, elevation 772 m (2,532 ft).
- Data quality: Representative (10+ years), 18 years of freeze data.
- Average days per year at or below 32°F: 42.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Globe #3 (34 km)
- Miami (40 km)
- Fort Thomas 2 SW (54 km)
- Superior (55 km)
- San Manuel (65 km)
- Oracle State Park (66 km)
- Oracle 2 SE (67 km)
- Roosevelt 1 S (75 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.