Frost dates for Moroni, UT
At Moroni, the median last spring frost (32°F) is May 26 and the median first fall frost is Sep 25, for a typical growing season of 119 days. For a 90% chance that the last frost has passed, wait until Jun 13. Nearby ZIP codes are in USDA hardiness zones 5b to 6a.
- May 26Last spring frost (median)50% chance of 32°F after this date
- Jun 13Safer planting date10% chance of 32°F after this date
- Sep 25First fall frost (median)50% chance of 32°F by this date
- 119 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 27 | Jun 10 | Jun 28 |
| 32°F | May 10 | May 26 | Jun 13 |
| 28°F | Apr 25 | May 10 | May 30 |
| 24°F | Apr 11 | Apr 27 | May 11 |
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 1 | Sep 16 | Sep 27 |
| 32°F | Sep 9 | Sep 25 | Oct 8 |
| 28°F | Sep 21 | Oct 5 | Oct 20 |
| 24°F | Oct 1 | Oct 17 | Nov 1 |
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 | 70 days | 94 days | 115 days |
| 32°F | 98 days | 119 days | 141 days |
| 28°F | 121 days | 147 days | 168 days |
| 24°F | 150 days | 172 days | 193 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 |
|---|---|---|---|
| 84646 | 5b | -15 to -10°F | 2 km |
| 84667 | 5b | -15 to -10°F | 7 km |
| 84623 | 5b | -15 to -10°F | 8 km |
| 84662 | 6a | -10 to -5°F | 13 km |
| 84632 | 5b | -15 to -10°F | 14 km |
| 84647 | 5b | -15 to -10°F | 15 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 USC00425837, at 39.5267, -111.5872, elevation 1701 m (5,580 ft).
- Data quality: Representative (10+ years), 21 years of freeze data.
- Average days per year at or below 32°F: 189.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Ephraim (19 km)
- Levan (24 km)
- Manti Radio Kmti (29 km)
- Nephi (29 km)
- Manti (30 km)
- Electric Lake (33 km)
- Scofield-Skyline Mine (37 km)
- Scofield Dam (49 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.