Frost dates for Bonesteel, SD
At Bonesteel, the median last spring frost (32°F) is May 3 and the median first fall frost is Oct 10, for a typical growing season of 159 days. For a 90% chance that the last frost has passed, wait until May 15. Nearby ZIP codes are in USDA hardiness zone 5a.
- May 3Last spring frost (median)50% chance of 32°F after this date
- May 15Safer planting date10% chance of 32°F after this date
- Oct 10First fall frost (median)50% chance of 32°F by this date
- 159 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 30 | May 12 | May 25 |
| 32°F | Apr 19 | May 3 | May 15 |
| 28°F | Apr 8 | Apr 23 | May 6 |
| 24°F | Mar 31 | Apr 12 | Apr 25 |
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 17 | Sep 30 | Oct 13 |
| 32°F | Sep 26 | Oct 10 | Oct 22 |
| 28°F | Oct 3 | Oct 19 | Nov 1 |
| 24°F | Oct 15 | Oct 28 | Nov 11 |
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 | 140 days | 158 days |
| 32°F | 139 days | 159 days | 177 days |
| 28°F | 156 days | 178 days | 199 days |
| 24°F | 177 days | 198 days | 218 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 |
|---|---|---|---|
| 57317 | 5a | -20 to -15°F | 7 km |
| 57571 | 5a | -20 to -15°F | 12 km |
| 57538 | 5a | -20 to -15°F | 17 km |
| 68755 | 5a | -20 to -15°F | 22 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 USC00390778, at 43.0778, -98.9508, elevation 605 m (1,985 ft).
- Data quality: Representative (10+ years), 12 years of freeze data.
- Average days per year at or below 32°F: 162.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Pickstown 4ssw (33 km)
- Pickstown (34 km)
- Gregory (43 km)
- Academy 2ne (47 km)
- Wagner (54 km)
- Armour (55 km)
- White Lake (71 km)
- Chamberlain 5 S (79 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.