Frost dates for Sheridan Co Airport, WY
At Sheridan Co Airport, the median last spring frost (32°F) is May 21 and the median first fall frost is Sep 23, for a typical growing season of 123 days. For a 90% chance that the last frost has passed, wait until Jun 6. Nearby ZIP codes are in USDA hardiness zone 5a.
- May 21Last spring frost (median)50% chance of 32°F after this date
- Jun 6Safer planting date10% chance of 32°F after this date
- Sep 23First fall frost (median)50% chance of 32°F by this date
- 123 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 21 | Jun 4 | Jun 19 |
| 32°F | May 7 | May 21 | Jun 6 |
| 28°F | Apr 25 | May 7 | May 22 |
| 24°F | Apr 10 | Apr 25 | May 10 |
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 | Aug 30 | Sep 13 | Sep 25 |
| 32°F | Sep 9 | Sep 23 | Oct 6 |
| 28°F | Sep 20 | Oct 3 | Oct 17 |
| 24°F | Sep 28 | Oct 13 | Oct 26 |
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 | 78 days | 98 days | 118 days |
| 32°F | 102 days | 123 days | 143 days |
| 28°F | 126 days | 147 days | 166 days |
| 24°F | 148 days | 169 days | 191 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 |
|---|---|---|---|
| 82801 | 5a | -20 to -15°F | 9 km |
| 82844 | 5a | -20 to -15°F | 18 km |
| 82845 | 5a | -20 to -15°F | 19 km |
| 82842 | 5a | -20 to -15°F | 22 km |
| 82833 | 5a | -20 to -15°F | 24 km |
| 82832 | 5a | -20 to -15°F | 24 km |
| 82839 | 5a | -20 to -15°F | 27 km |
| 59025 | 5a | -20 to -15°F | 41 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 USW00024029, at 44.7694, -106.9689, elevation 1202 m (3,945 ft).
- Data quality: Standard (24+ years of data), 29 years of freeze data.
- Average days per year at or below 32°F: 185.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Big Horn (10 km)
- Sheridan Field Station (13 km)
- Story (22 km)
- Dayton (26 km)
- Burgess Junction (44 km)
- Clearmont 5 SW (46 km)
- Buffalo Johnson Co Airport (47 km)
- Buffalo (51 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.