Frost dates for Cordova Wastewater Plant, AK
At Cordova Wastewater Plant, the median last spring frost (32°F) is Apr 29 and the median first fall frost is Oct 13, for a typical growing season of 169 days. For a 90% chance that the last frost has passed, wait until May 13. Nearby ZIP codes are in USDA hardiness zones 4b to 8a.
- Apr 29Last spring frost (median)50% chance of 32°F after this date
- May 13Safer planting date10% chance of 32°F after this date
- Oct 13First fall frost (median)50% chance of 32°F by this date
- 169 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 | Apr 30 | May 14 | May 27 |
| 32°F | Apr 9 | Apr 29 | May 13 |
| 28°F | Mar 25 | Apr 10 | Apr 30 |
| 24°F | Mar 12 | Apr 1 | Apr 19 |
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 12 | Sep 29 | Oct 18 |
| 32°F | Sep 25 | Oct 13 | Nov 4 |
| 28°F | Oct 5 | Oct 27 | Nov 21 |
| 24°F | Oct 17 | Nov 8 | Dec 5 |
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 | 113 days | 135 days | 161 days |
| 32°F | 142 days | 169 days | 196 days |
| 28°F | 171 days | 198 days | 226 days |
| 24°F | 193 days | 222 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% |
Closest ZIP codes (each is closer to another station)
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 99686 | 5a | -20 to -15°F | 61 km |
| 99677 | 8a | 10 to 15°F | 63 km |
| 99573 | 4b | -25 to -20°F | 115 km |
| 99574 | 5a | -20 to -15°F | 118 km |
| 99693 | 7a | 0 to 5°F | 128 km |
| 99674 | 4b | -25 to -20°F | 170 km |
| 99587 | 5b | -15 to -10°F | 175 km |
| 99566 | 4b | -25 to -20°F | 190 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 USC00502179, at 60.5358, -145.7780, elevation 3 m (10 ft).
- Data quality: Estimated from nearby stations (2+ years), 12 years of freeze data.
- Average days per year at or below 32°F: 124.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Cordova N (3 km)
- Cordova M K Smith Airport (19 km)
- Valdez WSO (73 km)
- Valdez (74 km)
- Cannery Creek (108 km)
- Main Bay (127 km)
- Tonsina (128 km)
- Wally Noerenberg Hatchery (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.