Frost dates for Basin, WY
At Basin, the median last spring frost (32°F) is Apr 28 and the median first fall frost is Oct 10, for a typical growing season of 164 days. For a 90% chance that the last frost has passed, wait until May 11. Nearby ZIP codes are in USDA hardiness zone 4b.
- Apr 28Last spring frost (median)50% chance of 32°F after this date
- May 11Safer planting date10% chance of 32°F after this date
- Oct 10First fall frost (median)50% chance of 32°F by this date
- 164 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 27 | May 7 | May 21 |
| 32°F | Apr 15 | Apr 28 | May 11 |
| 28°F | Mar 31 | Apr 17 | May 1 |
| 24°F | Mar 14 | Apr 2 | Apr 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 15 | Sep 29 | Oct 12 |
| 32°F | Sep 26 | Oct 10 | Oct 22 |
| 28°F | Oct 7 | Oct 20 | Nov 1 |
| 24°F | Oct 15 | Oct 28 | Nov 10 |
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 | 123 days | 142 days | 159 days |
| 32°F | 144 days | 164 days | 182 days |
| 28°F | 167 days | 187 days | 206 days |
| 24°F | 187 days | 208 days | 230 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 |
|---|---|---|---|
| 82410 | 4b | -25 to -20°F | 10 km |
| 82432 | 4b | -25 to -20°F | 24 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 USC00480540, at 44.3797, -108.0350, elevation 1170 m (3,840 ft).
- Data quality: Standard (24+ years of data), 26 years of freeze data.
- Average days per year at or below 32°F: 176.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Greybull (12 km)
- Greybull S Big Horn Airport (16 km)
- Shell (27 km)
- Emblem (31 km)
- Worland (41 km)
- Worland (47 km)
- Lovell (59 km)
- Burgess Junction (60 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.