Last spring frost
Mar 24
Frost Dates for Schwana, WA
First fall frost
Nov 4
Growing season
222 days
Hardiness zone
7a
In an average year around Schwana, WA, the last spring frost (32°F) is about Mar 24 and the first fall frost is about Nov 4, giving roughly a 222-day growing season. To be safe most years, wait until Mar 4 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) | Apr 26 | Apr 9 | Mar 27 |
| Freeze (32°F) | Apr 7 | Mar 24 | Mar 4 |
| Hard (28°F) | Mar 25 | Mar 5 | Feb 17 |
| Severe (24°F) | Mar 9 | Feb 22 | Jan 27 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 26 | Apr 20 | Apr 16 | Apr 12 | Apr 9 | Apr 6 | Apr 3 | Mar 31 | Mar 27 |
| 32°F | Apr 7 | Apr 3 | Mar 31 | Mar 28 | Mar 24 | Mar 19 | Mar 15 | Mar 10 | Mar 4 |
| 28°F | Mar 25 | Mar 17 | Mar 12 | Mar 8 | Mar 5 | Mar 2 | Feb 28 | Feb 24 | Feb 17 |
| 24°F | Mar 9 | Mar 4 | Mar 1 | Feb 26 | Feb 22 | Feb 18 | Feb 13 | Feb 7 | Jan 27 |
| 20°F | Mar 1 | Feb 23 | Feb 18 | Feb 13 | Feb 7 | Feb 1 | Jan 23 | Jan 14 | Jan 2 |
| 16°F | Feb 21 | Feb 13 | Feb 6 | Jan 31 | Jan 23 | Jan 16 | Jan 10 | Jan 2 | Dec 21 |
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) | Oct 14 | Oct 25 | Nov 6 |
| Freeze (32°F) | Oct 23 | Nov 4 | Nov 18 |
| Hard (28°F) | Nov 1 | Nov 16 | Dec 2 |
| Severe (24°F) | Nov 10 | Nov 29 | Dec 22 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 14 | Oct 17 | Oct 21 | Oct 23 | Oct 25 | Oct 28 | Oct 30 | Nov 2 | Nov 6 |
| 32°F | Oct 23 | Oct 27 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 9 | Nov 14 | Nov 18 |
| 28°F | Nov 1 | Nov 5 | Nov 9 | Nov 12 | Nov 16 | Nov 19 | Nov 22 | Nov 26 | Dec 2 |
| 24°F | Nov 10 | Nov 16 | Nov 21 | Nov 25 | Nov 29 | Dec 2 | Dec 7 | Dec 13 | Dec 22 |
| 20°F | Nov 21 | Nov 28 | Dec 3 | Dec 7 | Dec 12 | Dec 17 | Dec 25 | Jan 1 | Jan 15 |
| 16°F | Nov 29 | Dec 5 | Dec 11 | Dec 17 | Dec 24 | Dec 31 | Jan 7 | Jan 16 | Jan 31 |
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: Priest Rapids Dam, Wa, about 12.1 miles away@if(!empty($station['elevation_ft'])), at 428 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 Schwana, WA?
On average, the last spring frost (32°F) around Schwana, WA is about Mar 24. In cooler years it can run later, so for a safer bet many gardeners wait until Mar 4.
When is the first frost in the fall?
The first fall frost around Schwana, WA typically arrives about Nov 4. 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 Mar 24 on average, or Mar 4 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 222 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 98950 Planting calendar → Washington frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026