Frost dates for Maricopa 4 N, AZ
At Maricopa 4 N, the median last spring frost (32°F) is Feb 23 and the median first fall frost is Nov 24, for a typical growing season of 274 days. For a 90% chance that the last frost has passed, wait until Mar 15. Nearby ZIP codes are in USDA hardiness zones 9a to 9b.
- Feb 23Last spring frost (median)50% chance of 32°F after this date
- Mar 15Safer planting date10% chance of 32°F after this date
- Nov 24First fall frost (median)50% chance of 32°F by this date
- 274 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 | Feb 24 | Mar 12 | Apr 10 |
| 32°F | Jan 29 | Feb 23 | Mar 15 |
| 28°F | Dec 31 | Feb 2 | Feb 28 |
| 24°F | Dec 16 | Jan 8 | 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 | Oct 27 | Nov 14 | Nov 28 |
| 32°F | Nov 10 | Nov 24 | Dec 8 |
| 28°F | Nov 21 | Dec 6 | Dec 23 |
| 24°F | Dec 1 | Dec 18 | 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 | 215 days | 243 days | 267 days |
| 32°F | 245 days | 274 days | 304 days |
| 28°F | 278 days | 310 days | 344 days |
| 24°F | 314 days | 345 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 99% |
| 24°F | 85% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 85121 | 9b | 25 to 30°F | 11 km |
| 85138 | 9a | 20 to 25°F | 11 km |
| 85139 | 9a | 20 to 25°F | 27 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 USC00025270, at 33.1139, -112.0303, elevation 354 m (1,160 ft).
- Data quality: Representative (10+ years), 22 years of freeze data.
- Average days per year at or below 32°F: 32.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Laveen 3 SSE (27 km)
- South Phoenix (30 km)
- Chandler Heights (34 km)
- Phoenix Sky Harbor Intl Airport (35 km)
- Tempe Asu (36 km)
- Casa Grande (39 km)
- Casa Grande National Monument (48 km)
- E Mesa (49 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.