Frost dates for Snoqualmie Falls, WA
At Snoqualmie Falls, the median last spring frost (32°F) is Mar 30 and the median first fall frost is Nov 7, for a typical growing season of 223 days. For a 90% chance that the last frost has passed, wait until Apr 21. Nearby ZIP codes are in USDA hardiness zone 8b.
- Mar 30Last spring frost (median)50% chance of 32°F after this date
- Apr 21Safer planting date10% chance of 32°F after this date
- Nov 7First fall frost (median)50% chance of 32°F by this date
- 223 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 8 | Apr 26 | May 13 |
| 32°F | Mar 4 | Mar 30 | Apr 21 |
| 28°F | Jan 16 | Feb 27 | Mar 25 |
| 24°F | Dec 6 | Jan 31 | Feb 28 |
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 22 | Nov 7 |
| 32°F | Oct 22 | Nov 7 | Dec 1 |
| 28°F | Nov 6 | Nov 29 | Dec 31 |
| 24°F | Nov 21 | Dec 18 | Feb 6 |
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 | 156 days | 180 days | 206 days |
| 32°F | 195 days | 223 days | 252 days |
| 28°F | 236 days | 277 days | 319 days |
| 24°F | 284 days | 328 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 99% |
| 24°F | 83% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 98024 | 8b | 15 to 20°F | 6 km |
| 98065 | 8b | 15 to 20°F | 8 km |
| 98050 | 8b | 15 to 20°F | 8 km |
| 98027 | 8b | 15 to 20°F | 12 km |
| 98029 | 8b | 15 to 20°F | 13 km |
| 98075 | 8b | 15 to 20°F | 16 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 USC00457773, at 47.5414, -121.8361, elevation 134 m (440 ft).
- Data quality: Representative (10+ years), 18 years of freeze data.
- Average days per year at or below 32°F: 54.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Cedar Lake (15 km)
- Landsburg (21 km)
- Tolt S Fk Rsvr (21 km)
- Palmer 3 ESE (26 km)
- Renton Muni Airport (29 km)
- Kent (34 km)
- Seattle Boeing Field (35 km)
- Seattle Sand Point Wsfo (35 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.