Frost dates for Andover #2, SD
At Andover #2, the median last spring frost (32°F) is May 6 and the median first fall frost is Oct 4, for a typical growing season of 150 days. For a 90% chance that the last frost has passed, wait until May 21. Nearby ZIP codes are in USDA hardiness zones 4a to 4b.
- May 6Last spring frost (median)50% chance of 32°F after this date
- May 21Safer planting date10% chance of 32°F after this date
- Oct 4First fall frost (median)50% chance of 32°F by this date
- 150 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 16 | May 29 |
| 32°F | Apr 22 | May 6 | May 21 |
| 28°F | Apr 12 | Apr 28 | May 12 |
| 24°F | Apr 3 | Apr 18 | May 3 |
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 12 | Sep 26 | Oct 7 |
| 32°F | Sep 21 | Oct 4 | Oct 19 |
| 28°F | Oct 1 | Oct 14 | Oct 27 |
| 24°F | Oct 8 | Oct 24 | Nov 6 |
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 | 114 days | 133 days | 152 days |
| 32°F | 132 days | 150 days | 169 days |
| 28°F | 149 days | 168 days | 187 days |
| 24°F | 166 days | 187 days | 210 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 |
|---|---|---|---|
| 57422 | 4b | -25 to -20°F | 2 km |
| 57468 | 4b | -25 to -20°F | 16 km |
| 57219 | 4b | -25 to -20°F | 16 km |
| 57445 | 4a | -30 to -25°F | 17 km |
| 57439 | 4a | -30 to -25°F | 17 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 USC00390120, at 45.4133, -97.9067, elevation 450 m (1,478 ft).
- Data quality: Representative (10+ years), 16 years of freeze data.
- Average days per year at or below 32°F: 165.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Webster (31 km)
- Conde (33 km)
- Aberdeen (40 km)
- Aberdeen 3 E (40 km)
- Turton (43 km)
- Britton (43 km)
- Waubay National Wild Life (45 km)
- Columbia 8 N (46 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.