Frost dates for Window Rock Airport, AZ
At Window Rock Airport, the median last spring frost (32°F) is May 29 and the median first fall frost is Sep 28, for a typical growing season of 121 days. For a 90% chance that the last frost has passed, wait until Jun 10. Nearby ZIP codes are in USDA hardiness zone 6b.
- May 29Last spring frost (median)50% chance of 32°F after this date
- Jun 10Safer planting date10% chance of 32°F after this date
- Sep 28First fall frost (median)50% chance of 32°F by this date
- 121 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 | May 28 | Jun 8 | Jun 19 |
| 32°F | May 12 | May 29 | Jun 10 |
| 28°F | Apr 30 | May 13 | Jun 1 |
| 24°F | Apr 17 | May 2 | May 17 |
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 | Sep 9 | Sep 20 | Oct 1 |
| 32°F | Sep 16 | Sep 28 | Oct 8 |
| 28°F | Sep 23 | Oct 4 | Oct 20 |
| 24°F | Oct 1 | Oct 14 | Oct 30 |
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 | 88 days | 102 days | 118 days |
| 32°F | 104 days | 121 days | 140 days |
| 28°F | 122 days | 143 days | 163 days |
| 24°F | 143 days | 164 days | 185 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 86515 | 6b | -5 to 0°F | 9 km |
| 86504 | 6b | -5 to 0°F | 24 km |
| 87320 | 6b | -5 to 0°F | 24 km |
| 87328 | 6b | -5 to 0°F | 42 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 USW00003029, at 35.6575, -109.0614, elevation 2054 m (6,739 ft).
- Data quality: Representative (10+ years), 13 years of freeze data.
- Average days per year at or below 32°F: 196.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Ganado (45 km)
- Sanders (54 km)
- Canyon De Chelly (70 km)
- Lukachukai (86 km)
- Painted Desert National Park (92 km)
- Keams Canyon (104 km)
- Petrified Forest National Park (121 km)
- Holbrook (129 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.