Frost dates for Scappoose Ind Airport, OR
At Scappoose Ind Airport, the median last spring frost (32°F) is Apr 10 and the median first fall frost is Nov 2, for a typical growing season of 209 days. For a 90% chance that the last frost has passed, wait until May 1. Nearby ZIP codes are in USDA hardiness zone 8b.
- Apr 10Last spring frost (median)50% chance of 32°F after this date
- May 1Safer planting date10% chance of 32°F after this date
- Nov 2First fall frost (median)50% chance of 32°F by this date
- 209 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 15 | Apr 30 | May 17 |
| 32°F | Mar 17 | Apr 10 | May 1 |
| 28°F | Feb 2 | Mar 3 | Mar 28 |
| 24°F | Dec 19 | Feb 2 | Feb 28 |
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 1 | Oct 16 | Nov 3 |
| 32°F | Oct 16 | Nov 2 | Nov 23 |
| 28°F | Oct 31 | Nov 19 | Dec 15 |
| 24°F | Nov 9 | Dec 7 | Jan 16 |
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 | 148 days | 169 days | 191 days |
| 32°F | 182 days | 209 days | 238 days |
| 28°F | 226 days | 259 days | 300 days |
| 24°F | 269 days | 313 days | 357 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 94% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 97056 | 8b | 15 to 20°F | 9 km |
| 97231 | 8b | 15 to 20°F | 10 km |
| 98642 | 8b | 15 to 20°F | 13 km |
| 97133 | 8b | 15 to 20°F | 15 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 USW00004201, at 45.7728, -122.8611, elevation 17 m (55 ft).
- Data quality: Representative (10+ years), 22 years of freeze data.
- Average days per year at or below 32°F: 61.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Saint Helens Rfd (9 km)
- Portland-Hillsboro Airport (27 km)
- Vernonia #2 (28 km)
- Portland Intl Airport (29 km)
- Nature Park-Beaverton (31 km)
- Portland Kgw-Tv (31 km)
- Forest Grove (33 km)
- Portland WFO (34 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.