Frost dates for Pendleton Branch Exp. Station, OR
At Pendleton Branch Exp. Station, the median last spring frost (32°F) is May 12 and the median first fall frost is Sep 27, for a typical growing season of 135 days. For a 90% chance that the last frost has passed, wait until Jun 2. Nearby ZIP codes are in USDA hardiness zone 7a.
- May 12Last spring frost (median)50% chance of 32°F after this date
- Jun 2Safer planting date10% chance of 32°F after this date
- Sep 27First fall frost (median)50% chance of 32°F by this date
- 135 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 17 | Jun 5 | Jun 25 |
| 32°F | Apr 28 | May 12 | Jun 2 |
| 28°F | Apr 6 | Apr 27 | May 11 |
| 24°F | Mar 8 | Apr 5 | Apr 30 |
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 25 | Sep 9 | Sep 27 |
| 32°F | Sep 8 | Sep 27 | Oct 12 |
| 28°F | Sep 24 | Oct 10 | Oct 28 |
| 24°F | Oct 7 | Oct 26 | Nov 20 |
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 | 71 days | 97 days | 125 days |
| 32°F | 107 days | 135 days | 158 days |
| 28°F | 145 days | 168 days | 197 days |
| 24°F | 173 days | 205 days | 242 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 |
|---|---|---|---|
| 97835 | 7a | 0 to 5°F | 23 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 USC00356540, at 45.7206, -118.6264, elevation 453 m (1,487 ft).
- Data quality: Representative (10+ years), 25 years of freeze data.
- Average days per year at or below 32°F: 125.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Pendleton Dwtn (14 km)
- Pendleton WFO (18 km)
- Pendleton (18 km)
- Meacham (28 km)
- Milton Freewater (30 km)
- Pilot Rock 1 SE (31 km)
- Hermiston Muni Airport (51 km)
- Hermiston 2 NW (55 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.