Frost dates for Youngtown, AZ
At Youngtown, the median last spring frost (32°F) is Jan 20 and the median first fall frost is Dec 15, for a typical growing season of 331 days. For a 90% chance that the last frost has passed, wait until Feb 18. Nearby ZIP codes are in USDA hardiness zone 9b.
- Jan 20Last spring frost (median)50% chance of 32°F after this date
- Feb 18Safer planting date10% chance of 32°F after this date
- Dec 15First fall frost (median)50% chance of 32°F by this date
- 331 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 21 | Feb 14 | Mar 4 |
| 32°F | Dec 23 | Jan 20 | Feb 18 |
| 28°F | Dec 13 | Jan 3 | Feb 1 |
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 17 | Dec 2 | Dec 18 |
| 32°F | Nov 28 | Dec 15 | Jan 7 |
| 28°F | Dec 10 | Dec 29 | Jan 22 |
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 | 265 days | 291 days | 319 days |
| 32°F | 297 days | 331 days | 358 days |
| 28°F | 334 days | 365 days | 365 days |
| 24°F | 365 days | 365 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 95% |
| 28°F | 49% |
| 24°F | 6% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 85363 | 9b | 25 to 30°F | 1 km |
| 85351 | 9b | 25 to 30°F | 2 km |
| 85335 | 9b | 25 to 30°F | 3 km |
| 85345 | 9b | 25 to 30°F | 6 km |
| 85378 | 9b | 25 to 30°F | 6 km |
| 85381 | 9b | 25 to 30°F | 7 km |
| 85379 | 9b | 25 to 30°F | 7 km |
| 85373 | 9b | 25 to 30°F | 8 km |
| 85382 | 9b | 25 to 30°F | 8 km |
| 85305 | 9b | 25 to 30°F | 8 km |
| 85375 | 9b | 25 to 30°F | 10 km |
| 85303 | 9b | 25 to 30°F | 10 km |
| 85374 | 9b | 25 to 30°F | 10 km |
| 85304 | 9b | 25 to 30°F | 11 km |
| 85302 | 9b | 25 to 30°F | 12 km |
| 85388 | 9b | 25 to 30°F | 12 km |
| 85301 | 9b | 25 to 30°F | 13 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 USC00029634, at 33.5950, -112.3014, elevation 346 m (1,135 ft).
- Data quality: Standard (24+ years of data), 29 years of freeze data.
- Average days per year at or below 32°F: 4.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Litchfield Park (12 km)
- Phoenix Deer Valley Muni Airport (23 km)
- Wittmann 1se (29 km)
- South Phoenix (32 km)
- Laveen 3 SSE (32 km)
- Phoenix Sky Harbor Intl Airport (33 km)
- Scottsdale Muni Airport (36 km)
- Tempe Asu (40 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.