Last spring frost
Apr 23
Frost Dates for Weiser, ID
First fall frost
Oct 13
Growing season
174 days
Hardiness zone
7a
In an average year around Weiser, ID, the last spring frost (32°F) is about Apr 23 and the first fall frost is about Oct 13, giving roughly a 174-day growing season. To be safe most years, wait until Apr 3 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 26 | May 6 | Apr 22 |
| Freeze (32°F) | May 10 | Apr 23 | Apr 3 |
| Hard (28°F) | Apr 27 | Apr 3 | Mar 13 |
| Severe (24°F) | Apr 5 | Mar 11 | Feb 22 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 26 | May 18 | May 14 | May 9 | May 6 | May 2 | Apr 30 | Apr 27 | Apr 22 |
| 32°F | May 10 | May 4 | Apr 30 | Apr 26 | Apr 23 | Apr 19 | Apr 14 | Apr 10 | Apr 3 |
| 28°F | Apr 27 | Apr 19 | Apr 12 | Apr 7 | Apr 3 | Mar 31 | Mar 26 | Mar 18 | Mar 13 |
| 24°F | Apr 5 | Mar 30 | Mar 21 | Mar 15 | Mar 11 | Mar 8 | Mar 3 | Feb 28 | Feb 22 |
| 20°F | Mar 14 | Mar 7 | Mar 3 | Feb 28 | Feb 25 | Feb 21 | Feb 17 | Feb 11 | Feb 3 |
| 16°F | Mar 2 | Feb 25 | Feb 20 | Feb 16 | Feb 10 | Feb 6 | Feb 2 | Jan 26 | Jan 14 |
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 20 | Oct 4 | Oct 16 |
| Freeze (32°F) | Oct 1 | Oct 13 | Oct 27 |
| Hard (28°F) | Oct 12 | Oct 25 | Nov 7 |
| Severe (24°F) | Oct 20 | Nov 5 | Nov 23 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 20 | Sep 25 | Sep 29 | Oct 1 | Oct 4 | Oct 6 | Oct 9 | Oct 12 | Oct 16 |
| 32°F | Oct 1 | Oct 5 | Oct 8 | Oct 11 | Oct 13 | Oct 16 | Oct 19 | Oct 22 | Oct 27 |
| 28°F | Oct 12 | Oct 16 | Oct 19 | Oct 23 | Oct 25 | Oct 28 | Oct 31 | Nov 3 | Nov 7 |
| 24°F | Oct 20 | Oct 25 | Oct 30 | Nov 1 | Nov 5 | Nov 8 | Nov 12 | Nov 16 | Nov 23 |
| 20°F | Oct 31 | Nov 5 | Nov 10 | Nov 14 | Nov 18 | Nov 21 | Nov 24 | Nov 28 | Dec 5 |
| 16°F | Nov 10 | Nov 17 | Nov 22 | Nov 26 | Nov 29 | Dec 2 | Dec 7 | Dec 15 | Dec 26 |
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: Weiser, Id, about 8.9 miles away@if(!empty($station['elevation_ft'])), at 2,120 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 Weiser, ID?
On average, the last spring frost (32°F) around Weiser, ID is about Apr 23. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 3.
When is the first frost in the fall?
The first fall frost around Weiser, ID typically arrives about Oct 13. 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 23 on average, or Apr 3 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 174 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 83672 Planting calendar → Idaho frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026