Frost dates for Denali 27 N, AK
At Denali 27 N, the median last spring frost (32°F) is May 25 and the median first fall frost is Sep 8, for a typical growing season of 105 days. For a 90% chance that the last frost has passed, wait until Jun 3. Nearby ZIP codes are in USDA hardiness zones 2a to 4b.
- May 25Last spring frost (median)50% chance of 32°F after this date
- Jun 3Safer planting date10% chance of 32°F after this date
- Sep 8First fall frost (median)50% chance of 32°F by this date
- 105 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 26 | Jun 4 | Jun 16 |
| 32°F | May 13 | May 25 | Jun 3 |
| 28°F | May 3 | May 13 | May 24 |
| 24°F | Apr 22 | May 3 | May 13 |
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 | Aug 14 | Aug 27 | Sep 9 |
| 32°F | Aug 26 | Sep 8 | Sep 20 |
| 28°F | Sep 5 | Sep 19 | Sep 29 |
| 24°F | Sep 15 | Sep 27 | Oct 9 |
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 | 62 days | 82 days | 98 days |
| 32°F | 89 days | 105 days | 122 days |
| 28°F | 110 days | 126 days | 143 days |
| 24°F | 131 days | 147 days | 162 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
Closest ZIP codes (each is closer to another station)
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 99743 | 2a | -50 to -45°F | 69 km |
| 99757 | 2b | -45 to -40°F | 87 km |
| 99755 | 3b | -35 to -30°F | 89 km |
| 99676 | 4b | -25 to -20°F | 117 km |
| 99683 | 4b | -25 to -20°F | 118 km |
| 99704 | 2a | -50 to -45°F | 124 km |
| 99744 | 2a | -50 to -45°F | 132 km |
| 99760 | 2a | -50 to -45°F | 136 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 USW00096408, at 63.4519, -150.8747, elevation 678 m (2,225 ft).
- Data quality: Estimated from nearby stations (2+ years), 5 years of freeze data.
- Average days per year at or below 32°F: 230.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Chulitna River (85 km)
- Minchumina (86 km)
- Cantwell 2 E (99 km)
- McKinley Park (99 km)
- Healy (104 km)
- Kobe Hill (109 km)
- Clear Sky (121 km)
- Talkeetna Airport (132 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.