Frost dates for Stampede Pass, WA
At Stampede Pass, the median last spring frost (32°F) is May 14 and the median first fall frost is Oct 17, for a typical growing season of 154 days. For a 90% chance that the last frost has passed, wait until Jun 5. Nearby ZIP codes are in USDA hardiness zone 7a.
- May 14Last spring frost (median)50% chance of 32°F after this date
- Jun 5Safer planting date10% chance of 32°F after this date
- Oct 17First 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 20 | Jun 10 | Jun 30 |
| 32°F | Apr 26 | May 14 | Jun 5 |
| 28°F | Mar 31 | Apr 21 | May 12 |
| 24°F | Mar 1 | Mar 24 | Apr 17 |
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 14 | Oct 2 | Oct 15 |
| 32°F | Oct 1 | Oct 17 | Nov 1 |
| 28°F | Oct 18 | Nov 2 | Nov 18 |
| 24°F | Oct 30 | Nov 16 | Dec 2 |
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 | 86 days | 114 days | 139 days |
| 32°F | 123 days | 154 days | 178 days |
| 28°F | 165 days | 192 days | 219 days |
| 24°F | 205 days | 237 days | 264 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 |
|---|---|---|---|
| 98925 | 7a | 0 to 5°F | 5 km |
| 98068 | 7a | 0 to 5°F | 17 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 USW00024237, at 47.2767, -121.3372, elevation 1207 m (3,959 ft).
- Data quality: Representative (10+ years), 17 years of freeze data.
- Average days per year at or below 32°F: 165.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Easton (12 km)
- Cle Elum (33 km)
- Cedar Lake (35 km)
- Palmer 3 ESE (39 km)
- Mud Mountain Dam (48 km)
- Snoqualmie Falls (48 km)
- Landsburg (48 km)
- Buckley 1 NE (52 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.