Last spring frost
May 24
Frost Dates for Moore, ID
First fall frost
Sep 14
Growing season
113 days
Hardiness zone
5a
In an average year around Moore, ID, the last spring frost (32°F) is about May 24 and the first fall frost is about Sep 14, giving roughly a 113-day growing season. To be safe most years, wait until May 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) | Jul 2 | Jun 11 | May 24 |
| Freeze (32°F) | Jun 14 | May 24 | May 6 |
| Hard (28°F) | May 26 | May 5 | Apr 20 |
| Severe (24°F) | May 8 | Apr 23 | Apr 7 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jul 2 | Jun 25 | Jun 20 | Jun 15 | Jun 11 | Jun 8 | Jun 4 | May 31 | May 24 |
| 32°F | Jun 14 | Jun 7 | Jun 2 | May 29 | May 24 | May 19 | May 16 | May 11 | May 6 |
| 28°F | May 26 | May 17 | May 12 | May 9 | May 5 | May 2 | Apr 29 | Apr 25 | Apr 20 |
| 24°F | May 8 | May 3 | Apr 29 | Apr 26 | Apr 23 | Apr 20 | Apr 16 | Apr 11 | Apr 7 |
| 20°F | Apr 29 | Apr 22 | Apr 17 | Apr 13 | Apr 10 | Apr 6 | Apr 2 | Mar 29 | Mar 20 |
| 16°F | Apr 16 | Apr 9 | Apr 3 | Mar 30 | Mar 24 | Mar 17 | Mar 13 | Mar 9 | Mar 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) | Aug 20 | Sep 3 | Sep 16 |
| Freeze (32°F) | Sep 1 | Sep 14 | Sep 28 |
| Hard (28°F) | Sep 10 | Sep 25 | Oct 13 |
| Severe (24°F) | Sep 21 | Oct 8 | Oct 24 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Aug 20 | Aug 26 | Aug 29 | Sep 1 | Sep 3 | Sep 5 | Sep 8 | Sep 11 | Sep 16 |
| 32°F | Sep 1 | Sep 4 | Sep 8 | Sep 11 | Sep 14 | Sep 17 | Sep 20 | Sep 23 | Sep 28 |
| 28°F | Sep 10 | Sep 16 | Sep 20 | Sep 22 | Sep 25 | Sep 29 | Oct 2 | Oct 6 | Oct 13 |
| 24°F | Sep 21 | Sep 26 | Oct 1 | Oct 5 | Oct 8 | Oct 12 | Oct 16 | Oct 20 | Oct 24 |
| 20°F | Oct 4 | Oct 10 | Oct 15 | Oct 19 | Oct 22 | Oct 24 | Oct 27 | Oct 31 | Nov 3 |
| 16°F | Oct 17 | Oct 22 | Oct 26 | Oct 29 | Nov 1 | Nov 3 | Nov 5 | Nov 9 | Nov 15 |
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: Howe, Id, about 8.7 miles away@if(!empty($station['elevation_ft'])), at 4,820 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 Moore, ID?
On average, the last spring frost (32°F) around Moore, ID is about May 24. In cooler years it can run later, so for a safer bet many gardeners wait until May 6.
When is the first frost in the fall?
The first fall frost around Moore, ID typically arrives about Sep 14. 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 24 on average, or May 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 113 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 83244 Planting calendar → Idaho frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026