Last spring frost
Mar 31
Frost Dates for Salt Lake City, UT
First fall frost
Nov 8
Growing season
224 days
In an average year around Salt Lake City, UT, the last spring frost (32°F) is about Mar 31 and the first fall frost is about Nov 8, giving roughly a 224-day growing season. To be safe most years, wait until Mar 7 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 9 | Apr 18 | Mar 28 |
| Freeze (32°F) | Apr 19 | Mar 31 | Mar 7 |
| Hard (28°F) | Apr 2 | Mar 8 | Feb 17 |
| Severe (24°F) | Mar 10 | Feb 19 | Jan 31 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 9 | May 1 | Apr 26 | Apr 21 | Apr 18 | Apr 13 | Apr 8 | Apr 3 | Mar 28 |
| 32°F | Apr 19 | Apr 12 | Apr 7 | Apr 3 | Mar 31 | Mar 26 | Mar 19 | Mar 13 | Mar 7 |
| 28°F | Apr 2 | Mar 27 | Mar 15 | Mar 11 | Mar 8 | Mar 3 | Feb 28 | Feb 24 | Feb 17 |
| 24°F | Mar 10 | Mar 4 | Feb 28 | Feb 24 | Feb 19 | Feb 15 | Feb 11 | Feb 6 | Jan 31 |
| 20°F | Feb 27 | Feb 19 | Feb 13 | Feb 7 | Feb 3 | Jan 31 | Jan 26 | Jan 17 | Jan 3 |
| 16°F | Feb 13 | Feb 6 | Feb 1 | Jan 28 | Jan 22 | Jan 14 | Jan 7 | Dec 31 | Dec 20 |
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) | Oct 12 | Oct 28 | Nov 13 |
| Freeze (32°F) | Oct 23 | Nov 8 | Nov 25 |
| Hard (28°F) | Nov 1 | Nov 18 | Dec 6 |
| Severe (24°F) | Nov 11 | Nov 29 | Dec 17 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 12 | Oct 17 | Oct 22 | Oct 25 | Oct 28 | Oct 31 | Nov 3 | Nov 7 | Nov 13 |
| 32°F | Oct 23 | Oct 28 | Nov 1 | Nov 5 | Nov 8 | Nov 11 | Nov 15 | Nov 20 | Nov 25 |
| 28°F | Nov 1 | Nov 7 | Nov 11 | Nov 15 | Nov 18 | Nov 23 | Nov 26 | Dec 1 | Dec 6 |
| 24°F | Nov 11 | Nov 17 | Nov 21 | Nov 25 | Nov 29 | Dec 3 | Dec 7 | Dec 11 | Dec 17 |
| 20°F | Nov 19 | Nov 26 | Nov 30 | Dec 6 | Dec 11 | Dec 15 | Dec 20 | Dec 25 | Jan 3 |
| 16°F | Nov 28 | Dec 6 | Dec 14 | Dec 19 | Dec 25 | Dec 28 | Jan 2 | Jan 10 | Jan 24 |
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: Salt Lake Triad Ctr, Ut, about 0.6 miles away@if(!empty($station['elevation_ft'])), at 4,280 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 Salt Lake City, UT?
On average, the last spring frost (32°F) around Salt Lake City, UT is about Mar 31. In cooler years it can run later, so for a safer bet many gardeners wait until Mar 7.
When is the first frost in the fall?
The first fall frost around Salt Lake City, UT typically arrives about Nov 8. 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 Mar 31 on average, or Mar 7 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 224 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 84138 Planting calendar → Utah frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026