Frost dates for Aurora State Airport, OR
At Aurora State Airport, the median last spring frost (32°F) is Mar 16 and the median first fall frost is Nov 14, for a typical growing season of 242 days. For a 90% chance that the last frost has passed, wait until Apr 7. Nearby ZIP codes are in USDA hardiness zone 8b.
- Mar 16Last spring frost (median)50% chance of 32°F after this date
- Apr 7Safer planting date10% chance of 32°F after this date
- Nov 14First fall frost (median)50% chance of 32°F by this date
- 242 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 27 | Apr 15 | May 4 |
| 32°F | Feb 21 | Mar 16 | Apr 7 |
| 28°F | Jan 4 | Feb 15 | Mar 8 |
| 24°F | Dec 6 | Jan 12 | Feb 18 |
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 9 | Oct 26 | Nov 14 |
| 32°F | Oct 27 | Nov 14 | Dec 6 |
| 28°F | Nov 9 | Dec 1 | Dec 30 |
| 24°F | Nov 21 | Dec 17 | Jan 26 |
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 | 167 days | 193 days | 219 days |
| 32°F | 215 days | 242 days | 276 days |
| 28°F | 255 days | 292 days | 332 days |
| 24°F | 304 days | 340 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 | 76% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 97002 | 8b | 15 to 20°F | 2 km |
| 97020 | 8b | 15 to 20°F | 6 km |
| 97032 | 8b | 15 to 20°F | 8 km |
| 97013 | 8b | 15 to 20°F | 8 km |
| 97071 | 8b | 15 to 20°F | 14 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 USW00094281, at 45.2486, -122.7686, elevation 60 m (196 ft).
- Data quality: Representative (10+ years), 23 years of freeze data.
- Average days per year at or below 32°F: 39.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- N Willamette Exp. Station (4 km)
- Rex 1 S (13 km)
- Oregon City (18 km)
- Molalla 7ne (22 km)
- Beaverton 2 SSW (23 km)
- Silverton (27 km)
- Nature Park-Beaverton (28 km)
- McMinnville Muni Airport (29 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.