Frost dates for Evanston 1 E, WY
At Evanston 1 E, the median last spring frost (32°F) is Jun 12 and the median first fall frost is Sep 12, for a typical growing season of 90 days. For a 90% chance that the last frost has passed, wait until Jul 2. Nearby ZIP codes are in USDA hardiness zones 4a to 6a.
- Jun 12Last spring frost (median)50% chance of 32°F after this date
- Jul 2Safer planting date10% chance of 32°F after this date
- Sep 12First fall frost (median)50% chance of 32°F by this date
- 90 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 |
|---|---|---|---|
| 32°F | May 26 | Jun 12 | Jul 2 |
| 28°F | May 5 | May 24 | Jun 14 |
| 24°F | Apr 21 | May 5 | May 26 |
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 |
|---|---|---|---|
| 32°F | Aug 26 | Sep 12 | Sep 25 |
| 28°F | Sep 7 | Sep 24 | Oct 9 |
| 24°F | Sep 21 | Oct 6 | Oct 23 |
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 | 37 days | 63 days | 85 days |
| 32°F | 62 days | 90 days | 113 days |
| 28°F | 93 days | 121 days | 144 days |
| 24°F | 127 days | 151 days | 175 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 |
|---|---|---|---|
| 84086 | 5a | -20 to -15°F | 27 km |
| 82933 | 5b | -15 to -10°F | 38 km |
| 84017 | 5b | -15 to -10°F | 41 km |
| 82944 | 5a | -20 to -15°F | 41 km |
| 84018 | 6a | -10 to -5°F | 42 km |
| 82930 | 5a | -20 to -15°F | 45 km |
| 84064 | 4a | -30 to -25°F | 48 km |
| 84024 | 6a | -10 to -5°F | 50 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 USC00483100, at 41.2650, -110.9508, elevation 2080 m (6,825 ft).
- Data quality: Representative (10+ years), 24 years of freeze data.
- Average days per year at or below 32°F: 210.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Evanston Burns Field (7 km)
- Mountain View (51 km)
- Fossil Butte (65 km)
- Sage 4 NNW (67 km)
- Kemmerer 2n (71 km)
- Church Buttes Gas Plant (74 km)
- Fontenelle Dam (109 km)
- Buckboard Marina (113 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.