Frost dates for Eugene Mahlon Sweet Airport, OR
At Eugene Mahlon Sweet Airport, the median last spring frost (32°F) is Apr 11 and the median first fall frost is Oct 23, for a typical growing season of 196 days. For a 90% chance that the last frost has passed, wait until May 9. Nearby ZIP codes are in USDA hardiness zone 8b.
- Apr 11Last spring frost (median)50% chance of 32°F after this date
- May 9Safer planting date10% chance of 32°F after this date
- Oct 23First fall frost (median)50% chance of 32°F by this date
- 196 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 24 | May 15 | Jun 8 |
| 32°F | Mar 15 | Apr 11 | May 9 |
| 28°F | Feb 2 | Mar 3 | Mar 30 |
| 24°F | Dec 21 | Feb 1 | Feb 27 |
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 18 | Oct 7 | Oct 24 |
| 32°F | Oct 6 | Oct 23 | Nov 13 |
| 28°F | Oct 20 | Nov 11 | Dec 12 |
| 24°F | Nov 2 | Dec 5 | Jan 12 |
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 | 115 days | 144 days | 173 days |
| 32°F | 162 days | 196 days | 227 days |
| 28°F | 219 days | 252 days | 294 days |
| 24°F | 262 days | 307 days | 350 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 |
|---|---|---|---|
| 97404 | 8b | 15 to 20°F | 7 km |
| 97402 | 8b | 15 to 20°F | 9 km |
| 97448 | 8b | 15 to 20°F | 10 km |
| 97401 | 8b | 15 to 20°F | 13 km |
| 97408 | 8b | 15 to 20°F | 13 km |
| 97403 | 8b | 15 to 20°F | 17 km |
| 97477 | 8b | 15 to 20°F | 18 km |
| 97446 | 8b | 15 to 20°F | 20 km |
| 97405 | 8b | 15 to 20°F | 20 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 USW00024221, at 44.1278, -123.2206, elevation 108 m (353 ft).
- Data quality: Standard (24+ years of data), 25 years of freeze data.
- Average days per year at or below 32°F: 52.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Fern Ridge-Veneta (15 km)
- Corvallis 10 SSW (33 km)
- Cottage Grove 2e (40 km)
- Leaburg 1 SW (43 km)
- Dorena (44 km)
- Lookout Point Dam (44 km)
- Corvallis Water Bureau (46 km)
- Cottage Grove Dam (47 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.