Last spring frost
May 17
Frost Dates for Buhl, ID
First fall frost
Sep 29
Growing season
132 days
Hardiness zone
7a
In an average year around Buhl, ID, the last spring frost (32°F) is about May 17 and the first fall frost is about Sep 29, giving roughly a 132-day growing season. To be safe most years, wait until Apr 30 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) | Jun 20 | Jun 5 | May 18 |
| Freeze (32°F) | Jun 5 | May 17 | Apr 30 |
| Hard (28°F) | May 18 | Apr 30 | Apr 14 |
| Severe (24°F) | May 1 | Apr 13 | Mar 25 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jun 20 | Jun 16 | Jun 12 | Jun 8 | Jun 5 | Jun 2 | May 29 | May 24 | May 18 |
| 32°F | Jun 5 | May 31 | May 25 | May 20 | May 17 | May 14 | May 10 | May 6 | Apr 30 |
| 28°F | May 18 | May 11 | May 6 | May 3 | Apr 30 | Apr 28 | Apr 25 | Apr 20 | Apr 14 |
| 24°F | May 1 | Apr 25 | Apr 20 | Apr 17 | Apr 13 | Apr 9 | Apr 5 | Mar 31 | Mar 25 |
| 20°F | Apr 15 | Apr 9 | Apr 5 | Mar 31 | Mar 27 | Mar 20 | Mar 14 | Mar 7 | Feb 28 |
| 16°F | Mar 30 | Mar 15 | Mar 8 | Mar 3 | Feb 28 | Feb 24 | Feb 19 | Feb 13 | Feb 5 |
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 1 | Sep 16 | Oct 1 |
| Freeze (32°F) | Sep 11 | Sep 29 | Oct 15 |
| Hard (28°F) | Sep 26 | Oct 13 | Oct 28 |
| Severe (24°F) | Oct 8 | Oct 26 | Nov 10 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 1 | Sep 5 | Sep 9 | Sep 12 | Sep 16 | Sep 19 | Sep 22 | Sep 25 | Oct 1 |
| 32°F | Sep 11 | Sep 18 | Sep 22 | Sep 26 | Sep 29 | Oct 2 | Oct 5 | Oct 9 | Oct 15 |
| 28°F | Sep 26 | Oct 1 | Oct 5 | Oct 10 | Oct 13 | Oct 16 | Oct 19 | Oct 23 | Oct 28 |
| 24°F | Oct 8 | Oct 15 | Oct 19 | Oct 23 | Oct 26 | Oct 29 | Nov 1 | Nov 4 | Nov 10 |
| 20°F | Oct 20 | Oct 26 | Oct 30 | Nov 2 | Nov 6 | Nov 9 | Nov 12 | Nov 17 | Nov 23 |
| 16°F | Oct 30 | Nov 4 | Nov 8 | Nov 12 | Nov 16 | Nov 19 | Nov 23 | Nov 27 | Dec 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: Castleford 2 N, Id, about 5.3 miles away@if(!empty($station['elevation_ft'])), at 3,825 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 Buhl, ID?
On average, the last spring frost (32°F) around Buhl, ID is about May 17. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 30.
When is the first frost in the fall?
The first fall frost around Buhl, ID typically arrives about Sep 29. 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 May 17 on average, or Apr 30 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 132 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 83316 Planting calendar → Idaho frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026