Frost dates for Mobridge 2nnw, SD
At Mobridge 2nnw, the median last spring frost (32°F) is May 3 and the median first fall frost is Oct 8, for a typical growing season of 157 days. For a 90% chance that the last frost has passed, wait until May 16. Nearby ZIP codes are in USDA hardiness zone 4b.
- May 3Last spring frost (median)50% chance of 32°F after this date
- May 16Safer planting date10% chance of 32°F after this date
- Oct 8First fall frost (median)50% chance of 32°F by this date
- 157 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 1 | May 13 | May 27 |
| 32°F | Apr 20 | May 3 | May 16 |
| 28°F | Apr 11 | Apr 25 | May 9 |
| 24°F | Apr 4 | Apr 15 | May 1 |
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 19 | Sep 29 | Oct 13 |
| 32°F | Sep 25 | Oct 8 | Oct 21 |
| 28°F | Oct 2 | Oct 17 | Oct 29 |
| 24°F | Oct 11 | Oct 25 | Nov 7 |
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 | 122 days | 140 days | 158 days |
| 32°F | 138 days | 157 days | 174 days |
| 28°F | 154 days | 173 days | 191 days |
| 24°F | 173 days | 191 days | 211 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 |
|---|---|---|---|
| 57658 | 4b | -25 to -20°F | 15 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 USC00395691, at 45.5656, -100.4489, elevation 516 m (1,693 ft).
- Data quality: Representative (10+ years), 21 years of freeze data.
- Average days per year at or below 32°F: 169.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Mobridge Muni Airport (4 km)
- Selby (33 km)
- Mc Laughlin (39 km)
- Pollock (40 km)
- Timber Lake (51 km)
- Eureka (68 km)
- Mc Intosh 6 SE (71 km)
- Gettysburg (73 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.