Frost dates for Sunnyside City Center, UT
At Sunnyside City Center, the median last spring frost (32°F) is May 5 and the median first fall frost is Oct 15, for a typical growing season of 159 days. For a 90% chance that the last frost has passed, wait until May 26. Nearby ZIP codes are in USDA hardiness zones 6a to 6b.
- May 5Last spring frost (median)50% chance of 32°F after this date
- May 26Safer planting date10% chance of 32°F after this date
- Oct 15First fall frost (median)50% chance of 32°F by this date
- 159 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 4 | May 22 | Jun 9 |
| 32°F | Apr 21 | May 5 | May 26 |
| 28°F | Apr 8 | Apr 24 | May 12 |
| 24°F | Mar 23 | Apr 12 | Apr 30 |
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 16 | Oct 2 | Oct 19 |
| 32°F | Sep 30 | Oct 15 | Nov 1 |
| 28°F | Oct 9 | Oct 25 | Nov 10 |
| 24°F | Oct 18 | Nov 3 | Nov 19 |
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 | 109 days | 133 days | 158 days |
| 32°F | 134 days | 159 days | 182 days |
| 28°F | 159 days | 181 days | 204 days |
| 24°F | 180 days | 204 days | 227 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
Closest ZIP codes (each is closer to another station)
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 84539 | 6b | -5 to 0°F | 3 km |
| 84520 | 6b | -5 to 0°F | 4 km |
| 84542 | 6a | -10 to -5°F | 23 km |
| 84521 | 6a | -10 to -5°F | 36 km |
| 84501 | 6a | -10 to -5°F | 37 km |
| 84529 | 6b | -5 to 0°F | 38 km |
| 84518 | 6a | -10 to -5°F | 46 km |
| 84526 | 6a | -10 to -5°F | 52 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 USC00428478, at 39.5517, -110.3853, elevation 1990 m (6,530 ft).
- Data quality: Representative (10+ years), 16 years of freeze data.
- Average days per year at or below 32°F: 161.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Sunnyside City (0 km)
- Wellington 3 E (26 km)
- Price Carbon Co Airport (32 km)
- Castle Dale (66 km)
- Scofield Dam (68 km)
- Duchesne (69 km)
- Electric Lake (71 km)
- Scofield-Skyline Mine (72 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.