Last spring frost
Apr 29
Frost Dates for Kamiah, ID
First fall frost
Oct 5
Growing season
163 days
Hardiness zone
7a
In an average year around Kamiah, ID, the last spring frost (32°F) is about Apr 29 and the first fall frost is about Oct 5, giving roughly a 163-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 31 | May 11 | Apr 29 |
| Freeze (32°F) | May 12 | Apr 29 | Apr 9 |
| Hard (28°F) | Apr 29 | Apr 7 | Mar 19 |
| Severe (24°F) | Apr 8 | Mar 14 | Feb 20 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 31 | May 24 | May 18 | May 14 | May 11 | May 8 | May 5 | May 2 | Apr 29 |
| 32°F | May 12 | May 7 | May 3 | May 1 | Apr 29 | Apr 26 | Apr 21 | Apr 17 | Apr 9 |
| 28°F | Apr 29 | Apr 22 | Apr 16 | Apr 12 | Apr 7 | Apr 3 | Mar 30 | Mar 25 | Mar 19 |
| 24°F | Apr 8 | Mar 31 | Mar 25 | Mar 19 | Mar 14 | Mar 10 | Mar 5 | Feb 28 | Feb 20 |
| 20°F | Mar 18 | Mar 11 | Mar 6 | Mar 1 | Feb 26 | Feb 20 | Feb 14 | Feb 6 | Jan 28 |
| 16°F | Mar 5 | Feb 28 | Feb 21 | Feb 12 | Feb 6 | Feb 1 | Jan 22 | Jan 13 | Jan 4 |
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 5 | Sep 25 | Oct 9 |
| Freeze (32°F) | Sep 22 | Oct 5 | Oct 24 |
| Hard (28°F) | Oct 1 | Oct 20 | Nov 10 |
| Severe (24°F) | Oct 15 | Nov 6 | Nov 28 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 5 | Sep 13 | Sep 18 | Sep 22 | Sep 25 | Sep 28 | Oct 1 | Oct 3 | Oct 9 |
| 32°F | Sep 22 | Sep 27 | Sep 30 | Oct 3 | Oct 5 | Oct 9 | Oct 13 | Oct 17 | Oct 24 |
| 28°F | Oct 1 | Oct 6 | Oct 11 | Oct 16 | Oct 20 | Oct 24 | Oct 29 | Nov 3 | Nov 10 |
| 24°F | Oct 15 | Oct 22 | Oct 29 | Nov 2 | Nov 6 | Nov 10 | Nov 15 | Nov 21 | Nov 28 |
| 20°F | Oct 28 | Nov 4 | Nov 10 | Nov 15 | Nov 21 | Nov 27 | Dec 1 | Dec 7 | Dec 14 |
| 16°F | Nov 5 | Nov 14 | Nov 22 | Nov 28 | Dec 4 | Dec 8 | Dec 15 | Dec 21 | Jan 1 |
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: Kamiah, Id, about 1.3 miles away@if(!empty($station['elevation_ft'])), at 1,210 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 Kamiah, ID?
On average, the last spring frost (32°F) around Kamiah, ID is about Apr 29. 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 Kamiah, ID typically arrives about Oct 5. 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 29 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 163 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 83536 Planting calendar → Idaho frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026