Frost dates for Whidbey Island NAS, WA
At Whidbey Island NAS, the median last spring frost (32°F) is Mar 13 and the median first fall frost is Nov 14, for a typical growing season of 244 days. For a 90% chance that the last frost has passed, wait until Apr 1. Nearby ZIP codes are in USDA hardiness zone 8b.
- Mar 13Last spring frost (median)50% chance of 32°F after this date
- Apr 1Safer planting date10% chance of 32°F after this date
- Nov 14First fall frost (median)50% chance of 32°F by this date
- 244 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 | Mar 22 | Apr 9 | Apr 29 |
| 32°F | Feb 20 | Mar 13 | Apr 1 |
| 28°F | Jan 5 | Feb 18 | Mar 12 |
| 24°F | Dec 8 | Jan 24 | Feb 24 |
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 | Oct 6 | Oct 28 | Nov 17 |
| 32°F | Oct 26 | Nov 14 | Dec 5 |
| 28°F | Nov 9 | Dec 1 | Jan 6 |
| 24°F | Nov 19 | Dec 15 | Feb 2 |
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 | 173 days | 200 days | 226 days |
| 32°F | 217 days | 244 days | 277 days |
| 28°F | 255 days | 290 days | 331 days |
| 24°F | 294 days | 334 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 99% |
| 24°F | 82% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 98278 | 8b | 15 to 20°F | 1 km |
| 98277 | 8b | 15 to 20°F | 4 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 USW00024255, at 48.3500, -122.6667, elevation 14 m (47 ft).
- Data quality: Representative (10+ years), 21 years of freeze data.
- Average days per year at or below 32°F: 40.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Coupeville 1 S (16 km)
- Anacortes (18 km)
- Mount Vernon 3 WNW (23 km)
- Port Townsend (27 km)
- Olga 2 SE (31 km)
- Friday Harbor Airport (33 km)
- Sedro-Woolley (36 km)
- Sequim 2 E (42 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.