Last spring frost
May 31
Frost Dates for Gunnison, UT
First fall frost
Sep 21
Growing season
114 days
Hardiness zone
6a
In an average year around Gunnison, UT, the last spring frost (32°F) is about May 31 and the first fall frost is about Sep 21, giving roughly a 114-day growing season. To be safe most years, wait until May 12 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 29 | Jun 14 | May 31 |
| Freeze (32°F) | Jun 16 | May 31 | May 12 |
| Hard (28°F) | Jun 3 | May 11 | Apr 27 |
| Severe (24°F) | May 12 | Apr 28 | Apr 11 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jun 29 | Jun 24 | Jun 20 | Jun 17 | Jun 14 | Jun 11 | Jun 8 | Jun 4 | May 31 |
| 32°F | Jun 16 | Jun 10 | Jun 5 | Jun 2 | May 31 | May 28 | May 22 | May 18 | May 12 |
| 28°F | Jun 3 | May 26 | May 20 | May 15 | May 11 | May 8 | May 5 | May 1 | Apr 27 |
| 24°F | May 12 | May 8 | May 4 | May 1 | Apr 28 | Apr 24 | Apr 21 | Apr 17 | Apr 11 |
| 20°F | Apr 30 | Apr 23 | Apr 18 | Apr 14 | Apr 10 | Apr 6 | Apr 2 | Mar 28 | Mar 19 |
| 16°F | Apr 12 | Apr 3 | Mar 29 | Mar 23 | Mar 17 | Mar 13 | Mar 8 | Mar 3 | Feb 24 |
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 30 | Sep 12 | Sep 24 |
| Freeze (32°F) | Sep 8 | Sep 21 | Oct 2 |
| Hard (28°F) | Sep 17 | Sep 29 | Oct 15 |
| Severe (24°F) | Sep 27 | Oct 11 | Oct 27 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Aug 30 | Sep 3 | Sep 6 | Sep 9 | Sep 12 | Sep 14 | Sep 17 | Sep 20 | Sep 24 |
| 32°F | Sep 8 | Sep 12 | Sep 16 | Sep 19 | Sep 21 | Sep 23 | Sep 25 | Sep 28 | Oct 2 |
| 28°F | Sep 17 | Sep 21 | Sep 25 | Sep 27 | Sep 29 | Oct 2 | Oct 6 | Oct 9 | Oct 15 |
| 24°F | Sep 27 | Oct 1 | Oct 5 | Oct 8 | Oct 11 | Oct 15 | Oct 18 | Oct 21 | Oct 27 |
| 20°F | Oct 8 | Oct 13 | Oct 17 | Oct 21 | Oct 24 | Oct 27 | Oct 31 | Nov 3 | Nov 8 |
| 16°F | Oct 18 | Oct 23 | Oct 28 | Nov 1 | Nov 4 | Nov 7 | Nov 11 | Nov 15 | Nov 19 |
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: Manti Radio Kmti, Ut, about 11.5 miles away@if(!empty($station['elevation_ft'])), at 5,498 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 Gunnison, UT?
On average, the last spring frost (32°F) around Gunnison, UT is about May 31. In cooler years it can run later, so for a safer bet many gardeners wait until May 12.
When is the first frost in the fall?
The first fall frost around Gunnison, UT typically arrives about Sep 21. 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 31 on average, or May 12 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 114 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 84634 Planting calendar → Utah frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026