Frost dates for Trenton, UT
At Trenton, the median last spring frost (32°F) is May 17 and the median first fall frost is Sep 18, for a typical growing season of 121 days. For a 90% chance that the last frost has passed, wait until Jun 6. Nearby ZIP codes are in USDA hardiness zones 5b to 6a.
- May 17Last spring frost (median)50% chance of 32°F after this date
- Jun 6Safer planting date10% chance of 32°F after this date
- Sep 18First fall frost (median)50% chance of 32°F by this date
- 121 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 21 | Jun 5 | Jun 21 |
| 32°F | May 3 | May 17 | Jun 6 |
| 28°F | Apr 19 | May 2 | May 17 |
| 24°F | Mar 28 | Apr 17 | May 3 |
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 | Aug 23 | Sep 6 | Sep 21 |
| 32°F | Sep 1 | Sep 18 | Oct 4 |
| 28°F | Sep 15 | Oct 1 | Oct 16 |
| 24°F | Sep 28 | Oct 16 | Oct 31 |
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 | 67 days | 91 days | 112 days |
| 32°F | 98 days | 121 days | 142 days |
| 28°F | 127 days | 149 days | 171 days |
| 24°F | 155 days | 180 days | 205 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 |
|---|---|---|---|
| 84338 | 5b | -15 to -10°F | 2 km |
| 84308 | 6a | -10 to -5°F | 7 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 USC00428828, at 41.9153, -111.9128, elevation 1358 m (4,455 ft).
- Data quality: Representative (10+ years), 22 years of freeze data.
- Average days per year at or below 32°F: 180.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Richmond (9 km)
- Logan Cache Airport (15 km)
- Cutler Dam (15 km)
- Logan Radio Kvnu (21 km)
- Logan Utah St. Univ (21 km)
- Logan 5 SW Exp. Farm (28 km)
- Tremonton (31 km)
- Bear Lake State Park (43 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.