Frost dates for Monticello #2, UT
At Monticello #2, the median last spring frost (32°F) is May 17 and the median first fall frost is Oct 7, for a typical growing season of 141 days. For a 90% chance that the last frost has passed, wait until Jun 4. Nearby ZIP codes are in USDA hardiness zones 6b to 7a.
- May 17Last spring frost (median)50% chance of 32°F after this date
- Jun 4Safer planting date10% chance of 32°F after this date
- Oct 7First fall frost (median)50% chance of 32°F by this date
- 141 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 14 | May 31 | Jun 16 |
| 32°F | May 2 | May 17 | Jun 4 |
| 28°F | Apr 18 | May 2 | May 20 |
| 24°F | Apr 1 | Apr 17 | May 5 |
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 15 | Sep 29 | Oct 12 |
| 32°F | Sep 24 | Oct 7 | Oct 20 |
| 28°F | Oct 2 | Oct 17 | Nov 1 |
| 24°F | Oct 14 | Oct 29 | Nov 14 |
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 | 99 days | 121 days | 141 days |
| 32°F | 118 days | 141 days | 162 days |
| 28°F | 144 days | 166 days | 188 days |
| 24°F | 170 days | 193 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% |
Closest ZIP codes (each is closer to another station)
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 84535 | 6b | -5 to 0°F | 5 km |
| 84511 | 7a | 0 to 5°F | 38 km |
| 81324 | 6b | -5 to 0°F | 39 km |
| 84530 | 7a | 0 to 5°F | 42 km |
| 81411 | 6b | -5 to 0°F | 54 km |
| 81325 | 6b | -5 to 0°F | 56 km |
| 81320 | 6b | -5 to 0°F | 57 km |
| 81331 | 6b | -5 to 0°F | 61 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 USC00425807, at 37.8675, -109.3514, elevation 2160 m (7,086 ft).
- Data quality: Estimated from nearby stations (2+ years), 9 years of freeze data.
- Average days per year at or below 32°F: 169.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Monticello 2e (4 km)
- Cedar Point (29 km)
- Blanding (31 km)
- La Sal 1sw (49 km)
- Canyonlands-The Needles (49 km)
- Hovenweep National Monument (59 km)
- Natural Bridges National Monument (62 km)
- Bluff (68 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.