Last spring frost
May 4
Frost Dates for Santaquin, UT
First fall frost
Oct 11
Growing season
157 days
Hardiness zone
6b
In an average year around Santaquin, UT, the last spring frost (32°F) is about May 4 and the first fall frost is about Oct 11, giving roughly a 157-day growing season. To be safe most years, wait until Apr 18 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 8 | May 23 | May 3 |
| Freeze (32°F) | May 28 | May 4 | Apr 18 |
| Hard (28°F) | May 10 | Apr 19 | Mar 31 |
| Severe (24°F) | Apr 20 | Apr 1 | Mar 11 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jun 8 | Jun 4 | May 31 | May 27 | May 23 | May 18 | May 14 | May 9 | May 3 |
| 32°F | May 28 | May 19 | May 14 | May 8 | May 4 | May 1 | Apr 28 | Apr 24 | Apr 18 |
| 28°F | May 10 | May 1 | Apr 26 | Apr 22 | Apr 19 | Apr 15 | Apr 11 | Apr 7 | Mar 31 |
| 24°F | Apr 20 | Apr 14 | Apr 9 | Apr 5 | Apr 1 | Mar 29 | Mar 25 | Mar 18 | Mar 11 |
| 20°F | Apr 4 | Mar 28 | Mar 21 | Mar 15 | Mar 11 | Mar 7 | Mar 4 | Feb 28 | Feb 23 |
| 16°F | Mar 14 | Mar 7 | Mar 3 | Feb 28 | Feb 26 | Feb 21 | Feb 18 | Feb 12 | Feb 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) | Sep 18 | Oct 1 | Oct 15 |
| Freeze (32°F) | Sep 27 | Oct 11 | Oct 26 |
| Hard (28°F) | Oct 8 | Oct 23 | Nov 7 |
| Severe (24°F) | Oct 19 | Nov 3 | Nov 19 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 18 | Sep 23 | Sep 26 | Sep 29 | Oct 1 | Oct 3 | Oct 6 | Oct 9 | Oct 15 |
| 32°F | Sep 27 | Oct 1 | Oct 5 | Oct 8 | Oct 11 | Oct 14 | Oct 17 | Oct 21 | Oct 26 |
| 28°F | Oct 8 | Oct 12 | Oct 16 | Oct 20 | Oct 23 | Oct 27 | Oct 30 | Nov 3 | Nov 7 |
| 24°F | Oct 19 | Oct 24 | Oct 28 | Nov 1 | Nov 3 | Nov 7 | Nov 10 | Nov 13 | Nov 19 |
| 20°F | Oct 28 | Nov 2 | Nov 6 | Nov 9 | Nov 13 | Nov 17 | Nov 20 | Nov 23 | Nov 27 |
| 16°F | Nov 4 | Nov 10 | Nov 16 | Nov 19 | Nov 22 | Nov 25 | Nov 28 | Dec 1 | Dec 7 |
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: Santaquin Chlorinator, Ut, about 1.7 miles away@if(!empty($station['elevation_ft'])), at 5,160 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 Santaquin, UT?
On average, the last spring frost (32°F) around Santaquin, UT is about May 4. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 18.
When is the first frost in the fall?
The first fall frost around Santaquin, UT typically arrives about Oct 11. 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 4 on average, or Apr 18 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 157 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 84655 Planting calendar → Utah frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026