Last spring frost
May 8
Frost Dates for Benson, UT
First fall frost
Oct 2
Growing season
144 days
Hardiness zone
6a
In an average year around Benson, UT, the last spring frost (32°F) is about May 8 and the first fall frost is about Oct 2, giving roughly a 144-day growing season. To be safe most years, wait until Apr 24 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 17 | May 30 | May 10 |
| Freeze (32°F) | May 29 | May 8 | Apr 24 |
| Hard (28°F) | May 6 | Apr 22 | Apr 4 |
| Severe (24°F) | Apr 20 | Apr 1 | Mar 12 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jun 17 | Jun 11 | Jun 6 | Jun 3 | May 30 | May 24 | May 19 | May 15 | May 10 |
| 32°F | May 29 | May 20 | May 15 | May 11 | May 8 | May 5 | May 2 | Apr 30 | Apr 24 |
| 28°F | May 6 | May 2 | Apr 28 | Apr 25 | Apr 22 | Apr 18 | Apr 14 | Apr 10 | Apr 4 |
| 24°F | Apr 20 | Apr 14 | Apr 9 | Apr 4 | Apr 1 | Mar 28 | Mar 22 | Mar 17 | Mar 12 |
| 20°F | Mar 31 | Mar 25 | Mar 19 | Mar 15 | Mar 13 | Mar 10 | Mar 7 | Mar 4 | Feb 28 |
| 16°F | Mar 18 | Mar 13 | Mar 10 | Mar 7 | Mar 5 | Mar 3 | Feb 28 | Feb 25 | Feb 19 |
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 20 | Oct 4 |
| Freeze (32°F) | Sep 19 | Oct 2 | Oct 15 |
| Hard (28°F) | Sep 29 | Oct 13 | Oct 27 |
| Severe (24°F) | Oct 11 | Oct 25 | Nov 10 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 5 | Sep 10 | Sep 14 | Sep 17 | Sep 20 | Sep 23 | Sep 26 | Sep 30 | Oct 4 |
| 32°F | Sep 19 | Sep 23 | Sep 27 | Sep 30 | Oct 2 | Oct 5 | Oct 7 | Oct 10 | Oct 15 |
| 28°F | Sep 29 | Oct 3 | Oct 6 | Oct 10 | Oct 13 | Oct 16 | Oct 18 | Oct 22 | Oct 27 |
| 24°F | Oct 11 | Oct 16 | Oct 19 | Oct 23 | Oct 25 | Oct 28 | Nov 1 | Nov 4 | Nov 10 |
| 20°F | Oct 20 | Oct 26 | Oct 29 | Nov 1 | Nov 5 | Nov 8 | Nov 12 | Nov 17 | Nov 23 |
| 16°F | Oct 30 | Nov 5 | Nov 9 | Nov 13 | Nov 17 | Nov 22 | Nov 25 | Nov 29 | Dec 5 |
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: Logan Cache Ap, Ut, about 3 miles away@if(!empty($station['elevation_ft'])), at 4,454 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 Benson, UT?
On average, the last spring frost (32°F) around Benson, UT is about May 8. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 24.
When is the first frost in the fall?
The first fall frost around Benson, UT typically arrives about Oct 2. 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 8 on average, or Apr 24 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 144 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 84335 Planting calendar → Utah frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026