Frost dates for Glacier Bay, AK
At Glacier Bay, the median last spring frost (32°F) is May 6 and the median first fall frost is Oct 10, for a typical growing season of 154 days. For a 90% chance that the last frost has passed, wait until May 26. Nearby ZIP codes are in USDA hardiness zone 5b.
- May 6Last spring frost (median)50% chance of 32°F after this date
- May 26Safer planting date10% chance of 32°F after this date
- Oct 10First fall frost (median)50% chance of 32°F by this date
- 154 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 8 | May 24 | Jun 10 |
| 32°F | Apr 22 | May 6 | May 26 |
| 28°F | Apr 1 | Apr 20 | May 10 |
| 24°F | Mar 12 | Apr 3 | Apr 29 |
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 5 | Sep 26 | Oct 11 |
| 32°F | Sep 19 | Oct 10 | Oct 28 |
| 28°F | Sep 28 | Oct 28 | Nov 17 |
| 24°F | Oct 21 | Nov 13 | Dec 3 |
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 | 96 days | 122 days | 145 days |
| 32°F | 127 days | 154 days | 178 days |
| 28°F | 153 days | 186 days | 218 days |
| 24°F | 185 days | 221 days | 252 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 |
|---|---|---|---|
| 99827 | 5b | -15 to -10°F | 45 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 USC00503294, at 58.4561, -135.8692, elevation 14 m (45 ft).
- Data quality: Representative (10+ years), 21 years of freeze data.
- Average days per year at or below 32°F: 149.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Gustavus (11 km)
- Gustavus 2 NE (11 km)
- Elfin Cove (40 km)
- Hoonah (47 km)
- Pelican (59 km)
- Juneau Lena Point (65 km)
- Juneau Mile 17 (66 km)
- Auke Bay (72 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.