Last spring frost
May 24
Frost Dates for Marysvale, UT
First fall frost
Sep 25
Growing season
123 days
Hardiness zone
6a
In an average year around Marysvale, UT, the last spring frost (32°F) is about May 24 and the first fall frost is about Sep 25, giving roughly a 123-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) | Jun 26 | Jun 6 | May 23 |
| Freeze (32°F) | Jun 10 | May 24 | May 6 |
| Hard (28°F) | May 27 | May 8 | Apr 22 |
| Severe (24°F) | May 13 | Apr 24 | Apr 7 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jun 26 | Jun 20 | Jun 15 | Jun 9 | Jun 6 | Jun 2 | May 31 | May 28 | May 23 |
| 32°F | Jun 10 | Jun 4 | May 31 | May 28 | May 24 | May 21 | May 17 | May 12 | May 6 |
| 28°F | May 27 | May 21 | May 16 | May 12 | May 8 | May 5 | Apr 30 | Apr 27 | Apr 22 |
| 24°F | May 13 | May 6 | May 1 | Apr 27 | Apr 24 | Apr 20 | Apr 18 | Apr 13 | Apr 7 |
| 20°F | Apr 24 | Apr 17 | Apr 13 | Apr 9 | Apr 6 | Apr 3 | Mar 31 | Mar 26 | Mar 18 |
| 16°F | Apr 5 | Mar 30 | Mar 24 | Mar 19 | Mar 14 | Mar 10 | Mar 6 | Mar 2 | 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) | Sep 1 | Sep 15 | Sep 27 |
| Freeze (32°F) | Sep 11 | Sep 25 | Oct 6 |
| Hard (28°F) | Sep 20 | Oct 3 | Oct 18 |
| Severe (24°F) | Oct 1 | Oct 15 | Oct 31 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 1 | Sep 6 | Sep 9 | Sep 12 | Sep 15 | Sep 17 | Sep 20 | Sep 23 | Sep 27 |
| 32°F | Sep 11 | Sep 16 | Sep 19 | Sep 22 | Sep 25 | Sep 27 | Sep 30 | Oct 2 | Oct 6 |
| 28°F | Sep 20 | Sep 24 | Sep 28 | Oct 1 | Oct 3 | Oct 5 | Oct 8 | Oct 13 | Oct 18 |
| 24°F | Oct 1 | Oct 4 | Oct 8 | Oct 12 | Oct 15 | Oct 19 | Oct 22 | Oct 26 | Oct 31 |
| 20°F | Oct 12 | Oct 17 | Oct 21 | Oct 25 | Oct 28 | Oct 31 | Nov 2 | Nov 6 | Nov 11 |
| 16°F | Oct 24 | Oct 29 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 13 | Nov 17 | Nov 22 |
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: Marysvale, Ut, about 1.9 miles away@if(!empty($station['elevation_ft'])), at 5,845 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 Marysvale, UT?
On average, the last spring frost (32°F) around Marysvale, UT 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 Marysvale, UT typically arrives about Sep 25. 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 123 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 84750 Planting calendar → Utah frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026