Frost dates for Shadehill Rsvr, SD
At Shadehill Rsvr, the median last spring frost (32°F) is May 16 and the median first fall frost is Sep 24, for a typical growing season of 131 days. For a 90% chance that the last frost has passed, wait until May 29. Nearby ZIP codes are in USDA hardiness zone 4b.
- May 16Last spring frost (median)50% chance of 32°F after this date
- May 29Safer planting date10% chance of 32°F after this date
- Sep 24First fall frost (median)50% chance of 32°F by this date
- 131 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 14 | May 26 | Jun 6 |
| 32°F | May 6 | May 16 | May 29 |
| 28°F | Apr 23 | May 6 | May 19 |
| 24°F | Apr 11 | Apr 27 | 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 | Sep 1 | Sep 15 | Sep 29 |
| 32°F | Sep 9 | Sep 24 | Oct 6 |
| 28°F | Sep 19 | Oct 4 | Oct 16 |
| 24°F | Sep 27 | Oct 13 | Oct 24 |
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 | 92 days | 112 days | 130 days |
| 32°F | 112 days | 131 days | 148 days |
| 28°F | 130 days | 150 days | 168 days |
| 24°F | 148 days | 169 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 |
|---|---|---|---|
| 57638 | 4b | -25 to -20°F | 21 km |
| 57644 | 4b | -25 to -20°F | 27 km |
| 57634 | 4b | -25 to -20°F | 33 km |
| 57640 | 4b | -25 to -20°F | 35 km |
| 57620 | 4b | -25 to -20°F | 40 km |
| 57645 | 4b | -25 to -20°F | 50 km |
| 57649 | 4b | -25 to -20°F | 50 km |
| 58639 | 4b | -25 to -20°F | 52 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 USC00397569, at 45.6850, -102.2733, elevation 747 m (2,450 ft).
- Data quality: Representative (10+ years), 12 years of freeze data.
- Average days per year at or below 32°F: 188.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Bison (23 km)
- Lemmon (30 km)
- Lodgepole 5sw (41 km)
- Glad Valley 2 W (48 km)
- Ralph 1 N (62 km)
- Faith Muni Airport (75 km)
- Faith (76 km)
- Mc Intosh 6 SE (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.