Last spring frost
Apr 15
Frost Dates for Startup, WA
First fall frost
Oct 25
Growing season
192 days
Hardiness zone
8b
In an average year around Startup, WA, the last spring frost (32°F) is about Apr 15 and the first fall frost is about Oct 25, giving roughly a 192-day growing season. To be safe most years, wait until Mar 25 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) | May 24 | May 8 | Apr 20 |
| Freeze (32°F) | May 7 | Apr 15 | Mar 25 |
| Hard (28°F) | Apr 11 | Mar 18 | Feb 22 |
| Severe (24°F) | Mar 16 | Feb 19 | Jan 2 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 24 | May 20 | May 15 | May 11 | May 8 | May 4 | May 1 | Apr 26 | Apr 20 |
| 32°F | May 7 | May 1 | Apr 26 | Apr 20 | Apr 15 | Apr 10 | Apr 6 | Apr 1 | Mar 25 |
| 28°F | Apr 11 | Apr 3 | Mar 27 | Mar 22 | Mar 18 | Mar 13 | Mar 8 | Mar 2 | Feb 22 |
| 24°F | Mar 16 | Mar 7 | Mar 1 | Feb 25 | Feb 19 | Feb 13 | Feb 5 | Jan 22 | Jan 2 |
| 20°F | Feb 26 | Feb 16 | Feb 3 | Jan 22 | Jan 12 | Jan 2 | Dec 23 | Dec 14 | Dec 5 |
| 16°F | Jan 31 | Jan 13 | Jan 4 | Dec 31 | Dec 21 | Dec 16 | Dec 10 | Dec 5 | Nov 30 |
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 22 | Oct 7 | Oct 25 |
| Freeze (32°F) | Oct 5 | Oct 25 | Nov 15 |
| Hard (28°F) | Oct 23 | Nov 12 | Dec 12 |
| Severe (24°F) | Nov 7 | Dec 3 | Jan 14 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 22 | Sep 28 | Oct 1 | Oct 5 | Oct 7 | Oct 11 | Oct 15 | Oct 20 | Oct 25 |
| 32°F | Oct 5 | Oct 13 | Oct 17 | Oct 21 | Oct 25 | Oct 28 | Nov 1 | Nov 7 | Nov 15 |
| 28°F | Oct 23 | Oct 29 | Nov 2 | Nov 7 | Nov 12 | Nov 19 | Nov 26 | Dec 1 | Dec 12 |
| 24°F | Nov 7 | Nov 15 | Nov 22 | Nov 29 | Dec 3 | Dec 9 | Dec 18 | Dec 29 | Jan 14 |
| 20°F | Nov 18 | Nov 27 | Dec 2 | Dec 7 | Dec 14 | Dec 20 | Dec 30 | Jan 8 | Jan 29 |
| 16°F | Nov 23 | Dec 1 | Dec 5 | Dec 8 | Dec 13 | Dec 20 | Dec 28 | Jan 2 | Jan 18 |
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: Startup 1 E, Wa, about 3 miles away@if(!empty($station['elevation_ft'])), at 170 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 Startup, WA?
On average, the last spring frost (32°F) around Startup, WA is about Apr 15. In cooler years it can run later, so for a safer bet many gardeners wait until Mar 25.
When is the first frost in the fall?
The first fall frost around Startup, WA typically arrives about Oct 25. 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 Apr 15 on average, or Mar 25 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 192 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 98294 Planting calendar → Washington frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026