Frost dates for Cottonwood Weir, UT
At Cottonwood Weir, the median last spring frost (32°F) is Apr 29 and the median first fall frost is Oct 22, for a typical growing season of 174 days. For a 90% chance that the last frost has passed, wait until May 30. Nearby ZIP codes are in USDA hardiness zone 7b.
- Apr 29Last spring frost (median)50% chance of 32°F after this date
- May 30Safer planting date10% chance of 32°F after this date
- Oct 22First fall frost (median)50% chance of 32°F by this date
- 174 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 | Apr 25 | May 13 | Jun 9 |
| 32°F | Apr 10 | Apr 29 | May 30 |
| 28°F | Mar 21 | Apr 12 | May 13 |
| 24°F | Feb 28 | Mar 26 | Apr 19 |
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 27 | Oct 11 | Oct 27 |
| 32°F | Oct 6 | Oct 22 | Nov 7 |
| 28°F | Oct 17 | Nov 1 | Nov 18 |
| 24°F | Oct 24 | Nov 12 | Nov 28 |
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 | 122 days | 151 days | 175 days |
| 32°F | 143 days | 174 days | 200 days |
| 28°F | 168 days | 201 days | 231 days |
| 24°F | 199 days | 233 days | 262 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 |
|---|---|---|---|
| 84093 | 7b | 5 to 10°F | 5 km |
| 84117 | 7b | 5 to 10°F | 6 km |
| 84124 | 7b | 5 to 10°F | 7 km |
| 84094 | 7b | 5 to 10°F | 8 km |
| 84047 | 7b | 5 to 10°F | 9 km |
| 84107 | 7b | 5 to 10°F | 10 km |
| 84084 | 7b | 5 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 USC00421759, at 40.6189, -111.7836, elevation 1520 m (4,986 ft).
- Data quality: Standard (24+ years of data), 26 years of freeze data.
- Average days per year at or below 32°F: 112.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Alta (13 km)
- Salt Lake City E Bench (13 km)
- Mountain Dell Dam (15 km)
- Silver Lake Brighton (17 km)
- Alpine (17 km)
- Draper-Point Of Mountain (18 km)
- Salt Lake Triad Center (19 km)
- Timpanogos Cave (20 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.