Frost dates for Pelton Dam, OR
At Pelton Dam, the median last spring frost (32°F) is May 5 and the median first fall frost is Oct 7, for a typical growing season of 154 days. For a 90% chance that the last frost has passed, wait until May 29. Nearby ZIP codes are in USDA hardiness zone 7a.
- May 5Last spring frost (median)50% chance of 32°F after this date
- May 29Safer planting date10% chance of 32°F after this date
- Oct 7First fall frost (median)50% chance of 32°F by this date
- 154 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 8 | May 28 | Jun 20 |
| 32°F | Apr 21 | May 5 | May 29 |
| 28°F | Mar 30 | Apr 20 | May 7 |
| 24°F | Feb 27 | Mar 28 | 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 | Sep 7 | Sep 26 | Oct 8 |
| 32°F | Sep 24 | Oct 7 | Oct 22 |
| 28°F | Oct 4 | Oct 20 | Nov 4 |
| 24°F | Oct 17 | Nov 2 | Nov 27 |
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 | 90 days | 119 days | 145 days |
| 32°F | 128 days | 154 days | 175 days |
| 28°F | 157 days | 182 days | 208 days |
| 24°F | 189 days | 219 days | 253 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 |
|---|---|---|---|
| 97761 | 7a | 0 to 5°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 USC00356532, at 44.7275, -121.2506, elevation 430 m (1,410 ft).
- Data quality: Standard (24+ years of data), 28 years of freeze data.
- Average days per year at or below 32°F: 130.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Madras 2 N (11 km)
- Madras (23 km)
- Grizzly (34 km)
- Antelope 6 SSW (41 km)
- Redmond Roberts Field (53 km)
- Sisters (55 km)
- Marion Forks Fish Hatchery (57 km)
- Prineville (58 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.