Frost dates for Mayfield Power Plant, WA
At Mayfield Power Plant, the median last spring frost (32°F) is Apr 7 and the median first fall frost is Nov 13, for a typical growing season of 215 days. For a 90% chance that the last frost has passed, wait until May 8. Nearby ZIP codes are in USDA hardiness zones 8a to 8b.
- Apr 7Last spring frost (median)50% chance of 32°F after this date
- May 8Safer planting date10% chance of 32°F after this date
- Nov 13First fall frost (median)50% chance of 32°F by this date
- 215 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 17 | May 6 | May 23 |
| 32°F | Mar 16 | Apr 7 | May 8 |
| 28°F | Jan 31 | Mar 6 | Apr 2 |
| 24°F | Dec 12 | Jan 31 | Mar 1 |
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 | Oct 4 | Oct 24 | Nov 11 |
| 32°F | Oct 24 | Nov 13 | Dec 4 |
| 28°F | Nov 8 | Dec 1 | Jan 1 |
| 24°F | Nov 23 | Dec 19 | Feb 7 |
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 | 144 days | 171 days | 197 days |
| 32°F | 181 days | 215 days | 249 days |
| 28°F | 232 days | 269 days | 311 days |
| 24°F | 285 days | 328 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 85% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 98582 | 8b | 15 to 20°F | 3 km |
| 98585 | 8b | 15 to 20°F | 14 km |
| 98564 | 8a | 10 to 15°F | 15 km |
| 98570 | 8b | 15 to 20°F | 15 km |
| 98649 | 8a | 10 to 15°F | 22 km |
| 98533 | 8b | 15 to 20°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 USC00455110, at 46.5044, -122.5939, elevation 85 m (280 ft).
- Data quality: Representative (10+ years), 10 years of freeze data.
- Average days per year at or below 32°F: 66.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Toledo FAA Airport (17 km)
- Glenoma (35 km)
- Centralia (36 km)
- Longview (46 km)
- Olympia Airport (57 km)
- Cougar 6 E (58 km)
- Longmire Rainier NPS (66 km)
- Packwood (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.