Last spring frost
May 2
Frost Dates for Stevenson, WA
First fall frost
Oct 9
Growing season
161 days
Hardiness zone
8a
In an average year around Stevenson, WA, the last spring frost (32°F) is about May 2 and the first fall frost is about Oct 9, giving roughly a 161-day growing season. To be safe most years, wait until Apr 15 before setting out tender plants.
Last spring frost
Dates the last frost of spring typically ends. Plant tender crops after the risk has passed for your comfort level.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | Jun 10 | May 21 | May 6 |
| Freeze (32°F) | May 20 | May 2 | Apr 15 |
| Hard (28°F) | May 1 | Apr 7 | Mar 12 |
| Severe (24°F) | Mar 24 | Mar 1 | Jan 24 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jun 10 | Jun 3 | May 30 | May 25 | May 21 | May 18 | May 15 | May 11 | May 6 |
| 32°F | May 20 | May 13 | May 9 | May 5 | May 2 | Apr 30 | Apr 27 | Apr 23 | Apr 15 |
| 28°F | May 1 | Apr 25 | Apr 18 | Apr 12 | Apr 7 | Mar 31 | Mar 27 | Mar 21 | Mar 12 |
| 24°F | Mar 24 | Mar 15 | Mar 9 | Mar 3 | Mar 1 | Feb 25 | Feb 19 | Feb 11 | Jan 24 |
| 20°F | Mar 7 | Feb 28 | Feb 24 | Feb 17 | Feb 9 | Feb 1 | Jan 18 | Jan 7 | Dec 26 |
| 16°F | Mar 1 | Feb 23 | Feb 15 | Feb 6 | Jan 29 | Jan 16 | Jan 6 | Dec 29 | Dec 10 |
First fall frost
Dates the first frost of fall typically arrives. Count back by a crop's days-to-maturity to know your planting cutoff.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | Sep 7 | Sep 24 | Oct 11 |
| Freeze (32°F) | Sep 22 | Oct 9 | Nov 1 |
| Hard (28°F) | Oct 7 | Oct 30 | Nov 23 |
| Severe (24°F) | Oct 26 | Nov 23 | Dec 22 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 7 | Sep 11 | Sep 16 | Sep 21 | Sep 24 | Sep 29 | Oct 1 | Oct 5 | Oct 11 |
| 32°F | Sep 22 | Sep 28 | Oct 2 | Oct 6 | Oct 9 | Oct 13 | Oct 18 | Oct 24 | Nov 1 |
| 28°F | Oct 7 | Oct 16 | Oct 22 | Oct 27 | Oct 30 | Nov 2 | Nov 7 | Nov 13 | Nov 23 |
| 24°F | Oct 26 | Nov 3 | Nov 9 | Nov 16 | Nov 23 | Nov 27 | Dec 3 | Dec 10 | Dec 22 |
| 20°F | Nov 11 | Nov 22 | Nov 29 | Dec 5 | Dec 11 | Dec 20 | Dec 30 | Jan 7 | Jan 23 |
| 16°F | Nov 22 | Dec 1 | Dec 8 | Dec 18 | Dec 27 | Jan 1 | Jan 11 | Jan 25 | Feb 14 |
Growing season is measured at 32°F with about 50% probability. Hardiness zone from the 2023 USDA map; frost normals from NOAA 1991-2020.
Where this data comes from
@endif These dates are computed from the nearest official weather station with long-term records: Carson Fish Hatchery, Wa, about 6.8 miles away@if(!empty($station['elevation_ft'])), at 1,134 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.
How we calculate these dates
Frost and freeze dates come from the NOAA 1991–2020 U.S. Climate Normals, the National Oceanic and Atmospheric Administration's 30-year averages for each weather station. A date shown at the 50% level is the median: in half of years the frost falls on or before it. The 10% and 90% columns show the early and late ends of the range, so you can plant on the odds you're comfortable with. These are long-term averages, not a forecast for this year - always check your local outlook before planting.
Source: NOAA National Centers for Environmental Information, 1991–2020 Climate Normals (public domain). Harman is not affiliated with or endorsed by NOAA.
Frequently asked questions
When is the last frost in Stevenson, WA?
On average, the last spring frost (32°F) around Stevenson, WA is about May 2. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 15.
When is the first frost in the fall?
The first fall frost around Stevenson, WA typically arrives about Oct 9. Count back by a crop's days to maturity to find the latest date you can plant it.
When can I plant tomatoes and other tender crops?
Tender crops like tomatoes, peppers and basil are damaged by frost, so wait until the last spring frost has passed - around May 2 on average, or Apr 15 to be safe most years.
How long is the growing season here?
The frost-free growing season (between the last spring and first fall 32°F frost) is about 161 days in a typical year.
Are these dates a forecast for this year?
No. They are 30-year averages from the NOAA 1991–2020 Climate Normals, not a prediction for the current year. Use them for planning and always check your local weather forecast before planting or protecting crops.
Local weather for 98610 Planting calendar → Washington frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026