Last spring frost
Apr 25
Frost Dates for Kahlotus, WA
First fall frost
Oct 15
Growing season
173 days
Hardiness zone
7a
In an average year around Kahlotus, WA, the last spring frost (32°F) is about Apr 25 and the first fall frost is about Oct 15, giving roughly a 173-day growing season. To be safe most years, wait until Apr 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) | May 27 | May 10 | Apr 26 |
| Freeze (32°F) | May 11 | Apr 25 | Apr 4 |
| Hard (28°F) | Apr 25 | Apr 1 | Mar 7 |
| Severe (24°F) | Mar 30 | Mar 5 | Feb 10 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 27 | May 21 | May 17 | May 13 | May 10 | May 6 | May 3 | Apr 30 | Apr 26 |
| 32°F | May 11 | May 5 | May 1 | Apr 28 | Apr 25 | Apr 21 | Apr 17 | Apr 12 | Apr 4 |
| 28°F | Apr 25 | Apr 18 | Apr 11 | Apr 5 | Apr 1 | Mar 28 | Mar 22 | Mar 14 | Mar 7 |
| 24°F | Mar 30 | Mar 23 | Mar 15 | Mar 9 | Mar 5 | Mar 1 | Feb 25 | Feb 17 | Feb 10 |
| 20°F | Mar 11 | Mar 4 | Feb 28 | Feb 23 | Feb 17 | Feb 10 | Feb 4 | Jan 29 | Jan 16 |
| 16°F | Mar 1 | Feb 23 | Feb 16 | Feb 8 | Feb 2 | Jan 27 | Jan 17 | Jan 7 | Dec 28 |
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 5 | Oct 18 |
| Freeze (32°F) | Oct 2 | Oct 15 | Nov 1 |
| Hard (28°F) | Oct 10 | Oct 28 | Nov 16 |
| Severe (24°F) | Oct 22 | Nov 7 | Nov 28 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 22 | Sep 27 | Sep 30 | Oct 2 | Oct 5 | Oct 7 | Oct 10 | Oct 14 | Oct 18 |
| 32°F | Oct 2 | Oct 6 | Oct 10 | Oct 13 | Oct 15 | Oct 18 | Oct 22 | Oct 27 | Nov 1 |
| 28°F | Oct 10 | Oct 16 | Oct 21 | Oct 24 | Oct 28 | Oct 31 | Nov 3 | Nov 8 | Nov 16 |
| 24°F | Oct 22 | Oct 27 | Oct 31 | Nov 4 | Nov 7 | Nov 13 | Nov 18 | Nov 22 | Nov 28 |
| 20°F | Oct 31 | Nov 6 | Nov 11 | Nov 17 | Nov 22 | Nov 26 | Dec 1 | Dec 8 | Dec 17 |
| 16°F | Nov 10 | Nov 17 | Nov 25 | Nov 30 | Dec 5 | Dec 10 | Dec 16 | Dec 24 | Jan 6 |
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: Hatton 9 Se, Wa, about 11.4 miles away@if(!empty($station['elevation_ft'])), at 1,505 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 Kahlotus, WA?
On average, the last spring frost (32°F) around Kahlotus, WA is about Apr 25. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 4.
When is the first frost in the fall?
The first fall frost around Kahlotus, WA typically arrives about Oct 15. 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 25 on average, or Apr 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 173 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 99335 Planting calendar → Washington frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026