Frost dates for Humptulips Salmon Hatchery, WA
At Humptulips Salmon Hatchery, the median last spring frost (32°F) is Apr 26 and the median first fall frost is Oct 22, for a typical growing season of 180 days. For a 90% chance that the last frost has passed, wait until May 15. Nearby ZIP codes are in USDA hardiness zones 8b to 9a.
- Apr 26Last spring frost (median)50% chance of 32°F after this date
- May 15Safer planting date10% chance of 32°F after this date
- Oct 22First fall frost (median)50% chance of 32°F by this date
- 180 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 28 | May 16 | Jun 3 |
| 32°F | Mar 31 | Apr 26 | May 15 |
| 28°F | Feb 21 | Mar 27 | Apr 22 |
| 24°F | Dec 12 | Feb 16 | Mar 19 |
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 16 | Oct 3 | Oct 22 |
| 32°F | Oct 3 | Oct 22 | Nov 15 |
| 28°F | Oct 21 | Nov 13 | Dec 15 |
| 24°F | Nov 7 | Dec 7 | Jan 29 |
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 | 118 days | 141 days | 167 days |
| 32°F | 152 days | 180 days | 212 days |
| 28°F | 196 days | 233 days | 274 days |
| 24°F | 250 days | 302 days | 354 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 94% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 98536 | 9a | 20 to 25°F | 10 km |
| 98552 | 8b | 15 to 20°F | 10 km |
| 98550 | 8b | 15 to 20°F | 14 km |
| 98587 | 8b | 15 to 20°F | 16 km |
| 98562 | 9a | 20 to 25°F | 16 km |
| 98571 | 9a | 20 to 25°F | 16 km |
| 98535 | 9a | 20 to 25°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 USC00453826, at 47.2336, -123.9897, elevation 43 m (140 ft).
- Data quality: Standard (24+ years of data), 26 years of freeze data.
- Average days per year at or below 32°F: 73.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Aberdeen 20nne (21 km)
- Hoquiam Bowerman Airport (29 km)
- Aberdeen (32 km)
- Quinault 4 NE (34 km)
- Clearwater (44 km)
- Matlock 8 S (46 km)
- Grayland (49 km)
- Elma (51 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.