Last spring frost
May 15
Frost Dates for Rush Valley, UT
First fall frost
Oct 5
Growing season
142 days
Hardiness zone
6a
In an average year around Rush Valley, UT, the last spring frost (32°F) is about May 15 and the first fall frost is about Oct 5, giving roughly a 142-day growing season. To be safe most years, wait until Apr 27 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 15 | May 30 | May 12 |
| Freeze (32°F) | Jun 4 | May 15 | Apr 27 |
| Hard (28°F) | May 20 | Apr 30 | Apr 12 |
| Severe (24°F) | May 7 | Apr 16 | Mar 28 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jun 15 | Jun 9 | Jun 5 | Jun 1 | May 30 | May 26 | May 21 | May 17 | May 12 |
| 32°F | Jun 4 | May 28 | May 23 | May 19 | May 15 | May 11 | May 6 | May 1 | Apr 27 |
| 28°F | May 20 | May 13 | May 8 | May 4 | Apr 30 | Apr 27 | Apr 23 | Apr 19 | Apr 12 |
| 24°F | May 7 | Apr 30 | Apr 25 | Apr 20 | Apr 16 | Apr 12 | Apr 8 | Apr 3 | Mar 28 |
| 20°F | Apr 21 | Apr 13 | Apr 6 | Apr 1 | Mar 29 | Mar 24 | Mar 18 | Mar 12 | Mar 6 |
| 16°F | Apr 2 | Mar 24 | Mar 17 | Mar 11 | Mar 8 | Mar 4 | Mar 1 | Feb 23 | Feb 15 |
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 11 | Sep 25 | Oct 8 |
| Freeze (32°F) | Sep 22 | Oct 5 | Oct 22 |
| Hard (28°F) | Oct 1 | Oct 16 | Nov 1 |
| Severe (24°F) | Oct 12 | Oct 29 | Nov 14 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 11 | Sep 16 | Sep 20 | Sep 23 | Sep 25 | Sep 28 | Sep 30 | Oct 3 | Oct 8 |
| 32°F | Sep 22 | Sep 27 | Sep 30 | Oct 3 | Oct 5 | Oct 8 | Oct 13 | Oct 16 | Oct 22 |
| 28°F | Oct 1 | Oct 6 | Oct 10 | Oct 13 | Oct 16 | Oct 20 | Oct 23 | Oct 27 | Nov 1 |
| 24°F | Oct 12 | Oct 18 | Oct 22 | Oct 25 | Oct 29 | Nov 1 | Nov 4 | Nov 8 | Nov 14 |
| 20°F | Oct 23 | Oct 29 | Nov 1 | Nov 5 | Nov 8 | Nov 12 | Nov 16 | Nov 19 | Nov 24 |
| 16°F | Nov 2 | Nov 8 | Nov 12 | Nov 16 | Nov 19 | Nov 22 | Nov 25 | Nov 29 | Dec 4 |
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: Johnson Pass, Ut, about 6.9 miles away@if(!empty($station['elevation_ft'])), at 5,580 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 Rush Valley, UT?
On average, the last spring frost (32°F) around Rush Valley, UT is about May 15. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 27.
When is the first frost in the fall?
The first fall frost around Rush Valley, UT typically arrives about Oct 5. 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 15 on average, or Apr 27 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 142 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 84069 Planting calendar → Utah frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026