Frost dates for Prospect 2 SW, OR
At Prospect 2 SW, the median last spring frost (32°F) is May 19 and the median first fall frost is Oct 3, for a typical growing season of 136 days. For a 90% chance that the last frost has passed, wait until Jun 9. Nearby ZIP codes are in USDA hardiness zone 8a.
- May 19Last spring frost (median)50% chance of 32°F after this date
- Jun 9Safer planting date10% chance of 32°F after this date
- Oct 3First fall frost (median)50% chance of 32°F by this date
- 136 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 | May 22 | Jun 11 | Jun 28 |
| 32°F | Apr 29 | May 19 | Jun 9 |
| 28°F | Apr 1 | Apr 26 | May 16 |
| 24°F | Feb 14 | Mar 17 | Apr 21 |
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 | Aug 29 | Sep 14 | Oct 1 |
| 32°F | Sep 13 | Oct 3 | Oct 20 |
| 28°F | Oct 4 | Oct 24 | Nov 18 |
| 24°F | Oct 20 | Nov 17 | Dec 14 |
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 | 67 days | 95 days | 121 days |
| 32°F | 106 days | 136 days | 165 days |
| 28°F | 152 days | 182 days | 216 days |
| 24°F | 201 days | 243 days | 287 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 97536 | 8a | 10 to 15°F | 6 km |
| 97522 | 8a | 10 to 15°F | 13 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 USC00356907, at 42.7342, -122.5164, elevation 756 m (2,482 ft).
- Data quality: Standard (24+ years of data), 27 years of freeze data.
- Average days per year at or below 32°F: 116.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Lost Creek Dam (15 km)
- Crater Lake NPS HQ (36 km)
- Chiloquin 12 NW (fort Klamath) (43 km)
- Medford Rogue Valley Airport (49 km)
- Howard Prairie Dam (57 km)
- Ashland (60 km)
- Toketee Falls (60 km)
- Sexton Summit (71 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.