Frost dates / By state
Frost dates in South Dakota
NOAA 1991–2020 normals for a 32 °F freeze. Your own yard can run a little either side.
Short answer
Across 21 NOAA weather stations in South Dakota, the average last spring frost runs from April 27 at Yankton 2 E to May 23 at Custer Co Airport. The first fall frost comes as early as September 19 at Buffalo 13 ESE and as late as October 11 at Yankton 2 E. Planting zones near these stations run from 4a to 5a.
South Dakota cities
- Frost dates in Sioux Falls: last frost May 1, first frost October 6
Find yours by ZIP code
The table below is by weather station. For the station nearest you, and your planting zone, type your ZIP code.
South Dakota frost dates by weather station
| Station | Last spring frost | First fall frost | Frost-free | Zone nearby |
|---|---|---|---|---|
| Aberdeen 1,302 ft | May 9 1 in 10 after May 22 | September 26 1 in 10 by September 14 | 140 days | 4a |
| Aberdeen 35 WNW 1,957 ft | May 10 1 in 10 after May 22 | September 30 1 in 10 by September 19 | 143 days | 4b |
| Buffalo 13 ESE 2,883 ft | May 20 1 in 10 after June 2 | September 19 1 in 10 by September 3 | 122 days | – |
| Buffalo ASOS 3,004 ft | May 10 1 in 10 after May 23 | October 1 1 in 10 by September 16 | 144 days | 4b |
| Chamberlain Muni Airport 1,703 ft | May 1 1 in 10 after May 14 | October 7 1 in 10 by September 23 | 159 days | 5a |
| Custer Co Airport 5,545 ft | May 23 1 in 10 after June 6 | September 24 1 in 10 by September 9 | 124 days | 5a |
| Faith Muni Airport 2,580 ft | May 7 1 in 10 after May 20 | October 3 1 in 10 by September 19 | 149 days | 4b |
| Huron Rgnl Airport 1,280 ft | May 6 1 in 10 after May 20 | October 2 1 in 10 by September 19 | 149 days | 4b |
| Mitchell Muni Airport 1,303 ft | April 30 1 in 10 after May 13 | October 5 1 in 10 by September 22 | 158 days | 5a |
| Mobridge Muni Airport 1,715 ft | May 5 1 in 10 after May 20 | October 4 1 in 10 by September 21 | 152 days | 4b |
| Philip Airport 2,206 ft | May 11 1 in 10 after May 24 | September 30 1 in 10 by September 17 | 142 days | 5a |
| Pierre 24 S 2,124 ft | May 6 1 in 10 after May 20 | October 7 1 in 10 by September 22 | 154 days | 5a |
| Pierre Rgnl Airport 1,742 ft | May 6 1 in 10 after May 21 | October 3 1 in 10 by September 20 | 150 days | – |
| Pine Ridge Airport 3,278 ft | May 16 1 in 10 after May 31 | September 27 1 in 10 by September 13 | 134 days | 5a |
| Rapid City Rgnl Airport 3,160 ft | May 12 1 in 10 after May 26 | October 1 1 in 10 by September 16 | 142 days | 5a |
| Sioux Falls 1,430 ft | May 1 1 in 10 after May 14 | October 6 1 in 10 by September 23 | 158 days | 5a |
| Sioux Falls 14 NNE 1,594 ft | May 1 1 in 10 after May 15 | October 4 1 in 10 by September 21 | 156 days | 5a |
| Sisseton Muni Airport 1,161 ft | May 3 1 in 10 after May 16 | September 30 1 in 10 by September 17 | 150 days | 4b |
| Watertown Rgnl Airport 1,748 ft | May 7 1 in 10 after May 20 | September 30 1 in 10 by September 19 | 146 days | 4b |
| Winner Wiley Fld 2,032 ft | May 1 1 in 10 after May 15 | October 10 1 in 10 by September 27 | 162 days | – |
| Yankton 2 E 1,180 ft | April 27 1 in 10 after May 10 | October 11 1 in 10 by September 27 | 167 days | 5a |
The average date is NOAA's 50% date: half of years have a later last frost, or an earlier first one. Plan by the 1-in-10 date if a freeze would cost you plants. Stations are NOAA's main weather stations, mostly airports. “Zone nearby” is the USDA 2023 zone of the nearest ZIP code within 10 miles. NOAA counts the frost season from August to July, so in the warmest places the “first fall” freeze lands after New Year.
How these dates work
Frost dates come from NOAA's 1991 to 2020 Climate Normals, which work out from each weather station's daily lows how likely the last spring freeze and the first fall freeze (32 °F) are by each date. We use the station nearest the middle of your ZIP code and show its height and distance, since a station on a hill or by a lake can differ from your yard.
The average date is the 50% date: half of years have a freeze after the spring date or before the fall one. The 1-in-10 dates are NOAA's 10% dates, the ones to plan by if a late freeze would cost you plants. Within one yard, cold air pools in low spots while walls and paving hold heat, so some corners freeze before others.
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Where the numbers come from
- USDA Plant Hardiness Zone Map, 2023. Agricultural Research Service, U.S. Department of Agriculture
- PRISM Climate Group, Oregon State University (zone data)
- NOAA NCEI, U.S. Climate Normals 1991–2020, annual/seasonal
- NOAA, Normals calculation methodology (frost-freeze probability dates)
- US Census Bureau, 2025 ZCTA gazetteer (ZIP code centers)