Last spring frost
Apr 26
Frost Dates for Four Lakes, WA
First fall frost
Oct 12
Growing season
168 days
Hardiness zone
6b
In an average year around Four Lakes, WA, the last spring frost (32°F) is about Apr 26 and the first fall frost is about Oct 12, giving roughly a 168-day growing season. To be safe most years, wait until Apr 9 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 26 | May 8 | Apr 26 |
| Freeze (32°F) | May 10 | Apr 26 | Apr 9 |
| Hard (28°F) | Apr 28 | Apr 6 | Mar 15 |
| Severe (24°F) | Apr 4 | Mar 13 | Feb 26 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 26 | May 20 | May 15 | May 12 | May 8 | May 6 | May 3 | Apr 30 | Apr 26 |
| 32°F | May 10 | May 5 | May 2 | Apr 29 | Apr 26 | Apr 23 | Apr 20 | Apr 15 | Apr 9 |
| 28°F | Apr 28 | Apr 21 | Apr 15 | Apr 11 | Apr 6 | Apr 2 | Mar 29 | Mar 23 | Mar 15 |
| 24°F | Apr 4 | Mar 30 | Mar 25 | Mar 19 | Mar 13 | Mar 9 | Mar 6 | Mar 2 | Feb 26 |
| 20°F | Mar 17 | Mar 11 | Mar 7 | Mar 4 | Mar 1 | Feb 26 | Feb 21 | Feb 15 | Feb 6 |
| 16°F | Mar 8 | Mar 3 | Feb 28 | Feb 24 | Feb 19 | Feb 14 | Feb 6 | Jan 31 | Jan 15 |
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 17 | Oct 1 | Oct 14 |
| Freeze (32°F) | Sep 29 | Oct 12 | Oct 28 |
| Hard (28°F) | Oct 7 | Oct 23 | Nov 10 |
| Severe (24°F) | Oct 16 | Nov 3 | Nov 25 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 17 | Sep 23 | Sep 27 | Sep 29 | Oct 1 | Oct 4 | Oct 7 | Oct 10 | Oct 14 |
| 32°F | Sep 29 | Oct 3 | Oct 6 | Oct 9 | Oct 12 | Oct 15 | Oct 18 | Oct 22 | Oct 28 |
| 28°F | Oct 7 | Oct 13 | Oct 16 | Oct 20 | Oct 23 | Oct 27 | Oct 30 | Nov 3 | Nov 10 |
| 24°F | Oct 16 | Oct 22 | Oct 26 | Oct 30 | Nov 3 | Nov 7 | Nov 11 | Nov 17 | Nov 25 |
| 20°F | Oct 26 | Nov 2 | Nov 7 | Nov 12 | Nov 18 | Nov 22 | Nov 27 | Dec 1 | Dec 9 |
| 16°F | Nov 5 | Nov 13 | Nov 21 | Nov 25 | Nov 30 | Dec 3 | Dec 9 | Dec 15 | Dec 25 |
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: Spokane Intl Ap, Wa, about 5.3 miles away@if(!empty($station['elevation_ft'])), at 2,353 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 Four Lakes, WA?
On average, the last spring frost (32°F) around Four Lakes, WA is about Apr 26. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 9.
When is the first frost in the fall?
The first fall frost around Four Lakes, WA typically arrives about Oct 12. 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 26 on average, or Apr 9 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 168 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 99014 Planting calendar → Washington frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026