Frost dates for Boardman, OR
At Boardman, the median last spring frost (32°F) is Apr 14 and the median first fall frost is Oct 21, for a typical growing season of 188 days. For a 90% chance that the last frost has passed, wait until May 2. Nearby ZIP codes are in USDA hardiness zone 7b.
- Apr 14Last spring frost (median)50% chance of 32°F after this date
- May 2Safer planting date10% chance of 32°F after this date
- Oct 21First fall frost (median)50% chance of 32°F by this date
- 188 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 15 | May 1 | May 13 |
| 32°F | Mar 28 | Apr 14 | May 2 |
| 28°F | Mar 9 | Mar 28 | Apr 15 |
| 24°F | Feb 17 | Mar 8 | Mar 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 | Sep 27 | Oct 8 | Oct 22 |
| 32°F | Oct 5 | Oct 21 | Nov 4 |
| 28°F | Oct 17 | Nov 1 | Nov 19 |
| 24°F | Oct 26 | Nov 13 | Dec 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 | 143 days | 161 days | 181 days |
| 32°F | 167 days | 188 days | 210 days |
| 28°F | 194 days | 218 days | 242 days |
| 24°F | 224 days | 250 days | 282 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 |
|---|---|---|---|
| 99345 | 7b | 5 to 10°F | 10 km |
| 97818 | 7b | 5 to 10°F | 11 km |
| 97844 | 7b | 5 to 10°F | 12 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 USC00350858, at 45.8472, -119.6933, elevation 85 m (280 ft).
- Data quality: Standard (24+ years of data), 29 years of freeze data.
- Average days per year at or below 32°F: 104.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Hermiston 2 NW (30 km)
- McNary Dam #2 (32 km)
- Hermiston Muni Airport (34 km)
- Arlington (42 km)
- Heppner (55 km)
- Pendleton (67 km)
- Pendleton WFO (68 km)
- Pendleton Dwtn (72 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.