Last spring frost
Apr 26
Frost Dates for Loomis, WA
First fall frost
Oct 10
Growing season
168 days
Hardiness zone
6a
In an average year around Loomis, WA, the last spring frost (32°F) is about Apr 26 and the first fall frost is about Oct 10, giving roughly a 168-day growing season. To be safe most years, wait until Apr 6 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 29 | May 11 | Apr 27 |
| Freeze (32°F) | May 11 | Apr 26 | Apr 6 |
| Hard (28°F) | Apr 20 | Apr 1 | Mar 14 |
| Severe (24°F) | Mar 30 | Mar 12 | Feb 25 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 29 | May 23 | May 18 | May 15 | May 11 | May 8 | May 4 | Apr 30 | Apr 27 |
| 32°F | May 11 | May 5 | May 2 | Apr 29 | Apr 26 | Apr 21 | Apr 17 | Apr 11 | Apr 6 |
| 28°F | Apr 20 | Apr 13 | Apr 8 | Apr 4 | Apr 1 | Mar 30 | Mar 27 | Mar 22 | Mar 14 |
| 24°F | Mar 30 | Mar 25 | Mar 21 | Mar 16 | Mar 12 | Mar 9 | Mar 5 | Mar 2 | Feb 25 |
| 20°F | Mar 15 | Mar 9 | Mar 5 | Mar 2 | Feb 28 | Feb 25 | Feb 21 | Feb 16 | Feb 8 |
| 16°F | Mar 7 | Mar 1 | Feb 26 | Feb 20 | Feb 16 | Feb 10 | Feb 3 | Jan 27 | 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 15 | Sep 29 | Oct 12 |
| Freeze (32°F) | Sep 28 | Oct 10 | Oct 25 |
| Hard (28°F) | Oct 7 | Oct 23 | Nov 7 |
| Severe (24°F) | Oct 20 | Nov 3 | Nov 22 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 15 | Sep 21 | Sep 24 | Sep 27 | Sep 29 | Oct 1 | Oct 4 | Oct 7 | Oct 12 |
| 32°F | Sep 28 | Oct 1 | Oct 4 | Oct 7 | Oct 10 | Oct 14 | Oct 16 | Oct 21 | Oct 25 |
| 28°F | Oct 7 | Oct 13 | Oct 17 | Oct 20 | Oct 23 | Oct 27 | Oct 29 | Nov 2 | Nov 7 |
| 24°F | Oct 20 | Oct 25 | Oct 29 | Oct 31 | Nov 3 | Nov 6 | Nov 10 | Nov 15 | Nov 22 |
| 20°F | Oct 30 | Nov 3 | Nov 7 | Nov 10 | Nov 13 | Nov 17 | Nov 23 | Nov 29 | Dec 6 |
| 16°F | Nov 6 | Nov 12 | Nov 17 | Nov 23 | Nov 27 | Dec 1 | Dec 7 | Dec 19 | Dec 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: Tonasket 4 Nne, Wa, about 15.8 miles away@if(!empty($station['elevation_ft'])), at 960 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 Loomis, WA?
On average, the last spring frost (32°F) around Loomis, WA is about Apr 26. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 6.
When is the first frost in the fall?
The first fall frost around Loomis, WA typically arrives about Oct 10. 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 6 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 98827 Planting calendar → Washington frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026