Frost dates for Hoover, SD
At Hoover, the median last spring frost (32°F) is May 19 and the median first fall frost is Sep 21, for a typical growing season of 122 days. For a 90% chance that the last frost has passed, wait until May 31. Nearby ZIP codes are in USDA hardiness zone 4b.
- May 19Last spring frost (median)50% chance of 32°F after this date
- May 31Safer planting date10% chance of 32°F after this date
- Sep 21First fall frost (median)50% chance of 32°F by this date
- 122 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 17 | May 30 | Jun 12 |
| 32°F | May 7 | May 19 | May 31 |
| 28°F | Apr 28 | May 9 | May 23 |
| 24°F | Apr 15 | May 1 | May 14 |
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 28 | Sep 10 | Sep 23 |
| 32°F | Sep 6 | Sep 21 | Oct 3 |
| 28°F | Sep 16 | Sep 29 | Oct 10 |
| 24°F | Sep 24 | Oct 7 | Oct 19 |
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 | 82 days | 102 days | 121 days |
| 32°F | 104 days | 122 days | 141 days |
| 28°F | 122 days | 142 days | 160 days |
| 24°F | 141 days | 160 days | 179 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 |
|---|---|---|---|
| 57776 | 4b | -25 to -20°F | 23 km |
| 57760 | 4b | -25 to -20°F | 25 km |
| 57758 | 4b | -25 to -20°F | 44 km |
| 57651 | 4b | -25 to -20°F | 44 km |
| 57762 | 4b | -25 to -20°F | 49 km |
| 57649 | 4b | -25 to -20°F | 53 km |
| 57717 | 4b | -25 to -20°F | 53 km |
| 57720 | 4b | -25 to -20°F | 53 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 USC00393945, at 45.1125, -103.2683, elevation 845 m (2,773 ft).
- Data quality: Representative (10+ years), 13 years of freeze data.
- Average days per year at or below 32°F: 197.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Zeona 10 SSW (22 km)
- Redig 11 NE (30 km)
- Buffalo 13 ESE (45 km)
- Newell (46 km)
- Antelope Ranger Station (47 km)
- Belle Fourche 22 NNW (54 km)
- Buffalo Asos (59 km)
- Maurine 12sw (62 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.