Frost dates for Evanston Burns Field, WY
At Evanston Burns Field, the median last spring frost (32°F) is Jun 3 and the median first fall frost is Sep 25, for a typical growing season of 113 days. For a 90% chance that the last frost has passed, wait until Jun 17. Nearby ZIP codes are in USDA hardiness zones 4a to 6a.
- Jun 3Last spring frost (median)50% chance of 32°F after this date
- Jun 17Safer planting date10% chance of 32°F after this date
- Sep 25First fall frost (median)50% chance of 32°F by this date
- 113 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 31 | Jun 13 | Jun 24 |
| 32°F | May 16 | Jun 3 | Jun 17 |
| 28°F | Apr 29 | May 17 | Jun 6 |
| 24°F | Apr 17 | May 2 | May 20 |
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 26 |
| 32°F | Sep 11 | Sep 25 | Oct 8 |
| 28°F | Sep 19 | Oct 4 | Oct 21 |
| 24°F | Oct 1 | Oct 17 | Oct 31 |
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 | 75 days | 92 days | 110 days |
| 32°F | 92 days | 113 days | 135 days |
| 28°F | 113 days | 138 days | 161 days |
| 24°F | 137 days | 165 days | 188 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 | 21 km |
| 84018 | 6a | -10 to -5°F | 35 km |
| 84017 | 5b | -15 to -10°F | 38 km |
| 82933 | 5b | -15 to -10°F | 45 km |
| 84024 | 6a | -10 to -5°F | 46 km |
| 84064 | 4a | -30 to -25°F | 46 km |
| 82944 | 5a | -20 to -15°F | 47 km |
| 84317 | 6a | -10 to -5°F | 49 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 USW00004111, at 41.2731, -111.0306, elevation 2183 m (7,163 ft).
- Data quality: Representative (10+ years), 21 years of freeze data.
- Average days per year at or below 32°F: 193.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Evanston 1 E (7 km)
- Mountain View (58 km)
- Sage 4 NNW (66 km)
- Fossil Butte (66 km)
- Kemmerer 2n (73 km)
- Church Buttes Gas Plant (80 km)
- Fontenelle Dam (113 km)
- Buckboard Marina (120 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.