Last spring frost
Mar 25
Frost Dates for Halls Crossing, UT
First fall frost
Nov 10
Growing season
227 days
Hardiness zone
8a
In an average year around Halls Crossing, UT, the last spring frost (32°F) is about Mar 25 and the first fall frost is about Nov 10, giving roughly a 227-day growing season. To be safe most years, wait until Mar 8 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) | Apr 30 | Apr 11 | Mar 25 |
| Freeze (32°F) | Apr 12 | Mar 25 | Mar 8 |
| Hard (28°F) | Mar 22 | Mar 6 | Feb 18 |
| Severe (24°F) | Mar 7 | Feb 20 | Jan 27 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 30 | Apr 23 | Apr 19 | Apr 15 | Apr 11 | Apr 8 | Apr 4 | Mar 31 | Mar 25 |
| 32°F | Apr 12 | Apr 5 | Apr 1 | Mar 30 | Mar 25 | Mar 20 | Mar 16 | Mar 12 | Mar 8 |
| 28°F | Mar 22 | Mar 16 | Mar 11 | Mar 8 | Mar 6 | Mar 4 | Mar 1 | Feb 25 | Feb 18 |
| 24°F | Mar 7 | Mar 3 | Feb 28 | Feb 25 | Feb 20 | Feb 15 | Feb 11 | Feb 3 | Jan 27 |
| 20°F | Feb 23 | Feb 15 | Feb 9 | Feb 4 | Feb 1 | Jan 28 | Jan 21 | Jan 12 | Jan 2 |
| 16°F | Feb 7 | Jan 31 | Jan 25 | Jan 17 | Jan 11 | Jan 6 | Jan 1 | Dec 26 | Dec 17 |
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 16 | Oct 31 | Nov 12 |
| Freeze (32°F) | Oct 26 | Nov 10 | Nov 20 |
| Hard (28°F) | Nov 7 | Nov 20 | Dec 2 |
| Severe (24°F) | Nov 19 | Nov 29 | Dec 16 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 16 | Oct 21 | Oct 24 | Oct 28 | Oct 31 | Nov 3 | Nov 5 | Nov 8 | Nov 12 |
| 32°F | Oct 26 | Nov 1 | Nov 5 | Nov 8 | Nov 10 | Nov 12 | Nov 15 | Nov 17 | Nov 20 |
| 28°F | Nov 7 | Nov 12 | Nov 16 | Nov 18 | Nov 20 | Nov 22 | Nov 24 | Nov 27 | Dec 2 |
| 24°F | Nov 19 | Nov 22 | Nov 25 | Nov 27 | Nov 29 | Dec 2 | Dec 6 | Dec 10 | Dec 16 |
| 20°F | Nov 28 | Dec 1 | Dec 5 | Dec 9 | Dec 13 | Dec 17 | Dec 21 | Dec 25 | Jan 2 |
| 16°F | Dec 7 | Dec 12 | Dec 18 | Dec 22 | Dec 26 | Dec 31 | Jan 4 | Jan 11 | Jan 25 |
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: Bullfrog Basin, Ut, about 12.9 miles away@if(!empty($station['elevation_ft'])), at 3,822 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 Halls Crossing, UT?
On average, the last spring frost (32°F) around Halls Crossing, UT is about Mar 25. In cooler years it can run later, so for a safer bet many gardeners wait until Mar 8.
When is the first frost in the fall?
The first fall frost around Halls Crossing, UT typically arrives about Nov 10. 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 25 on average, or Mar 8 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 227 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 84533 Planting calendar → Utah frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026