Frost dates for Plain, WA
At Plain, the median last spring frost (32°F) is May 22 and the median first fall frost is Sep 22, for a typical growing season of 121 days. For a 90% chance that the last frost has passed, wait until Jun 13. Nearby ZIP codes are in USDA hardiness zone 7a.
- May 22Last spring frost (median)50% chance of 32°F after this date
- Jun 13Safer planting date10% chance of 32°F after this date
- Sep 22First fall frost (median)50% chance of 32°F by this date
- 121 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 24 | Jun 13 | Jul 1 |
| 32°F | May 2 | May 22 | Jun 13 |
| 28°F | Apr 19 | May 3 | May 20 |
| 24°F | Mar 21 | Apr 13 | May 3 |
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 24 | Sep 8 | Sep 21 |
| 32°F | Sep 7 | Sep 22 | Oct 4 |
| 28°F | Sep 22 | Oct 4 | Oct 20 |
| 24°F | Oct 4 | Oct 23 | Nov 9 |
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 | 62 days | 85 days | 108 days |
| 32°F | 97 days | 121 days | 144 days |
| 28°F | 128 days | 153 days | 177 days |
| 24°F | 166 days | 192 days | 220 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 |
|---|---|---|---|
| 98826 | 7a | 0 to 5°F | 15 km |
| 98822 | 7a | 0 to 5°F | 22 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 USC00456534, at 47.7850, -120.6456, elevation 590 m (1,936 ft).
- Data quality: Standard (24+ years of data), 30 years of freeze data.
- Average days per year at or below 32°F: 177.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Leavenworth 3 S (25 km)
- Entiat Fish Hatchery (26 km)
- Waterville (45 km)
- Wenatchee (47 km)
- Holden Village (47 km)
- Chelan (48 km)
- Wenatchee Pangborn Airport (54 km)
- Methow 2 S (60 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.