Frost dates for Rosette, UT
At Rosette, the median last spring frost (32°F) is May 21 and the median first fall frost is Oct 2, for a typical growing season of 132 days. For a 90% chance that the last frost has passed, wait until Jun 11. Nearby ZIP codes are in USDA hardiness zone 6a.
- May 21Last spring frost (median)50% chance of 32°F after this date
- Jun 11Safer planting date10% chance of 32°F after this date
- Oct 2First fall frost (median)50% chance of 32°F by this date
- 132 daysGrowing season (median)between 32°F freezes
Last spring frost dates
The chance that the temperature drops to the threshold after each date.
| Temperature | 90% chance later | 50% chance later | 10% chance later |
|---|---|---|---|
| 36°F | May 18 | Jun 4 | Jun 21 |
| 32°F | May 2 | May 21 | Jun 11 |
| 28°F | Apr 16 | May 3 | May 25 |
| 24°F | Mar 28 | Apr 18 | May 10 |
First fall frost dates
The chance that the temperature has dropped to the threshold by each date.
| Temperature | 10% chance by | 50% chance by | 90% chance by |
|---|---|---|---|
| 36°F | Sep 8 | Sep 24 | Oct 7 |
| 32°F | Sep 17 | Oct 2 | Oct 17 |
| 28°F | Sep 27 | Oct 12 | Oct 27 |
| 24°F | Oct 5 | Oct 23 | Nov 9 |
Growing season length
Days between the last spring and first fall freeze, as the length reached in 9, 5 and 1 out of 10 years.
| Temperature | 9 in 10 years at least | 5 in 10 years at least | 1 in 10 years at least |
|---|---|---|---|
| 36°F | 87 days | 109 days | 132 days |
| 32°F | 104 days | 132 days | 157 days |
| 28°F | 134 days | 161 days | 183 days |
| 24°F | 162 days | 188 days | 215 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 84329 | 6a | -10 to -5°F | 5 km |
Not the official USDA Plant Hardiness Zone Map. Zones shown here are the values published in the USDA-ARS / Oregon State University PRISM Group 2023 ZIP code tables, shown unaltered. For the official interactive map, visit planthardiness.ars.usda.gov.
About this station
- NOAA station ID USC00427408, at 41.8186, -113.4133, elevation 1733 m (5,685 ft).
- Data quality: Representative (10+ years), 23 years of freeze data.
- Average days per year at or below 32°F: 175.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Grouse Creek (40 km)
- Brigham City 28 WNW (76 km)
- Thiokol Propulsion F S (83 km)
- Utah Test Range (94 km)
- Tremonton (104 km)
- Cutler Dam (112 km)
- Brigham City Waste Plant (118 km)
- Trenton (125 km)
Sources
- NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020, annual/seasonal normals by station (version 1.0.1), file dated June 27, 2023; documentation.
- USDA Agricultural Research Service and PRISM Group, Oregon State University, 2023 Plant Hardiness Zone Map ZIP code tables (CONUS, Alaska, Hawaii, Puerto Rico), files dated November 17, 2023. Data © PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed November 1, 2026. Official map: planthardiness.ars.usda.gov.
- U.S. Census Bureau, 2024 Gazetteer ZIP Code Tabulation Areas file, dated August 30, 2024 (ZIP centroids used to find the nearest station).
Freeze dates are 30-year probabilities, not forecasts. Check your local forecast before planting tender plants.