Frost dates for Juneau Mile 17, AK
At Juneau Mile 17, the median last spring frost (32°F) is Apr 29 and the median first fall frost is Oct 20, for a typical growing season of 173 days. For a 90% chance that the last frost has passed, wait until May 10. Nearby ZIP codes are in USDA hardiness zones 5b to 7a.
- Apr 29Last spring frost (median)50% chance of 32°F after this date
- May 10Safer planting date10% chance of 32°F after this date
- Oct 20First fall frost (median)50% chance of 32°F by this date
- 173 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 2 | May 13 | May 25 |
| 32°F | Apr 15 | Apr 29 | May 10 |
| 28°F | Mar 28 | Apr 11 | Apr 26 |
| 24°F | Mar 7 | Mar 27 | Apr 9 |
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 21 | Oct 4 | Oct 17 |
| 32°F | Oct 2 | Oct 20 | Nov 3 |
| 28°F | Oct 20 | Nov 7 | Nov 23 |
| 24°F | Nov 5 | Nov 20 | Dec 12 |
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 | 125 days | 143 days | 161 days |
| 32°F | 153 days | 173 days | 192 days |
| 28°F | 186 days | 208 days | 231 days |
| 24°F | 217 days | 239 days | 268 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 |
|---|---|---|---|
| 99824 | 7a | 0 to 5°F | 26 km |
| 99801 | 6a | -10 to -5°F | 33 km |
| 99850 | 7a | 0 to 5°F | 44 km |
| 99829 | 7a | 0 to 5°F | 54 km |
| 99826 | 7a | 0 to 5°F | 62 km |
| 99841 | 7a | 0 to 5°F | 67 km |
| 99832 | 7a | 0 to 5°F | 92 km |
| 99827 | 5b | -15 to -10°F | 97 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 USC00504109, at 58.4058, -134.7467, elevation 75 m (245 ft).
- Data quality: Representative (10+ years), 12 years of freeze data.
- Average days per year at or below 32°F: 134.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Juneau Lena Point (2 km)
- Auke Bay (7 km)
- Juneau Forecast Office (10 km)
- Juneau Intl Airport (12 km)
- Eaglecrest Base (20 km)
- Juneau Dwtn (23 km)
- Annex Creek (39 km)
- Hoonah (52 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.