Frost dates for Winchester, OR
At Winchester, the median last spring frost (32°F) is Mar 31 and the median first fall frost is Nov 5, for a typical growing season of 215 days. For a 90% chance that the last frost has passed, wait until Apr 26. Nearby ZIP codes are in USDA hardiness zones 8b to 9a.
- Mar 31Last spring frost (median)50% chance of 32°F after this date
- Apr 26Safer planting date10% chance of 32°F after this date
- Nov 5First fall frost (median)50% chance of 32°F by this date
- 215 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 6 | Apr 28 | May 15 |
| 32°F | Mar 5 | Mar 31 | Apr 26 |
| 28°F | Jan 11 | Feb 26 | Mar 31 |
| 24°F | Nov 30 | Jan 20 | 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 2 | Oct 20 | Nov 6 |
| 32°F | Oct 16 | Nov 5 | Dec 3 |
| 28°F | Oct 29 | Dec 1 | Jan 10 |
| 24°F | Nov 12 | Dec 21 | Feb 8 |
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 | 149 days | 175 days | 199 days |
| 32°F | 187 days | 215 days | 254 days |
| 28°F | 236 days | 278 days | 325 days |
| 24°F | 303 days | 343 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 98% |
| 24°F | 66% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 97495 | 8b | 15 to 20°F | 3 km |
| 97494 | 8b | 15 to 20°F | 6 km |
| 97486 | 9a | 20 to 25°F | 16 km |
| 97479 | 8b | 15 to 20°F | 19 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 USC00359461, at 43.2828, -123.3536, elevation 140 m (460 ft).
- Data quality: Representative (10+ years), 23 years of freeze data.
- Average days per year at or below 32°F: 38.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Roseburg Regional Airport (5 km)
- Roseburg Kqen (8 km)
- Idleyld Park 4 NE (33 km)
- Riddle (37 km)
- Elkton 3 SW (40 km)
- Drain (42 km)
- Elkton 1sw (44 km)
- Cottage Grove Dam (54 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.