South Dakota frost dates: Last spring and first autumn frost at every NOAA station, 1991-2020
Across South Dakota's 166 NOAA stations with frost dates, the median last spring frost (32°F) runs from April 26 in Sioux Falls Weather Office Airport to June 1 in Hill City; for half of its places it comes after May 7.
- Typical last spring frost
- May 7median of 100 places
- Typical first autumn frost
- October 1median of 100 places
- Earliest last frost
- April 26Sioux Falls Weather Office Airport
- Latest last frost
- June 1Hill City
When is the last frost in South Dakota, town by town?
Each date is NOAA's: "after May 7 in half of years" means the last 32°F night of spring came after May 7 in half of the years 1991-2020. By the 1-in-10 date, the last frost has passed in nine years out of ten.
Find your town in the list, or look up a ZIP code for the stations nearest it.
| Place or station | Last frost (median) | 1 in 10 after | First frost (median) | 1 in 10 before | Growing season | Zone |
|---|---|---|---|---|---|---|
| Sioux Falls Weather Office Airport | April 26 | May 9 | October 13 | September 28 | 169 days | – |
| Mitchell station | April 27 | May 10 | October 11 | September 30 | 167 days | – |
| Pickstown (4 mi SSW) | April 27 | May 11 | October 13 | September 27 | 168 days | – |
| Yankton2 mi E | April 27 | May 10 | October 11 | September 27 | 164 days | – |
| Wagner | April 29 | May 12 | October 9 | September 25 | 164 days | 5a |
| Academy (2 mi NE) | April 30 | May 14 | October 8 | September 24 | 159 days | 5a |
| Bridgewater | April 30 | May 11 | October 7 | September 25 | 161 days | 4b |
| MitchellMitchell Airport | April 30 | May 13 | October 5 | September 22 | 159 days | 5a |
| Pickstown | April 30 | May 12 | October 13 | September 29 | 165 days | 5b |
| ChamberlainChamberlain Municipal Airport | May 1 | May 14 | October 7 | September 23 | 158 days | 5a |
| Menno | May 1 | May 14 | October 4 | September 21 | 156 days | 4b |
| Sioux FallsSioux Falls Foss Field | May 1 | May 14 | October 6 | September 23 | 157 days | 5a |
| Sioux Falls (14 mi NNE) | May 1 | May 15 | October 4 | September 21 | 155 days | – |
| Tyndall | May 1 | May 14 | October 7 | September 24 | 158 days | 5a |
| WaubayWaubay National Wild Life | May 1 | May 12 | October 12 | September 30 | 164 days | 4b |
| WinnerWinner Wiley Field | May 1 | May 15 | October 10 | September 27 | 162 days | 5b |
| Winner station | May 1 | May 16 | October 9 | September 25 | 159 days | 5b |
| Canton | May 2 | May 15 | October 2 | September 19 | 151 days | 4b |
| Centerville6 mi SE | May 2 | May 15 | October 1 | September 17 | 151 days | 4b |
| Milbank (4 mi NW) | May 2 | May 15 | October 4 | September 22 | 153 days | – |
| Mitchell (2 mi N) | May 2 | May 15 | October 6 | September 23 | 156 days | – |
| Roy Lake | May 2 | May 15 | October 9 | September 27 | 160 days | – |
| Wentworth2.5 mi WNW | May 2 | May 14 | October 5 | September 24 | 156 days | 4b |
| Wessington Springs | May 2 | May 14 | October 8 | September 26 | 157 days | 5a |
| Arlington1 mi W | May 3 | May 15 | October 2 | September 19 | 151 days | 4b |
| Armour | May 3 | May 18 | October 6 | September 23 | 157 days | – |
| Bonesteel | May 3 | May 15 | October 10 | September 26 | 159 days | – |
| Chamberlain (5 mi S) | May 3 | May 17 | October 7 | September 25 | 156 days | 5a |
| Miller | May 3 | May 16 | October 3 | September 20 | 152 days | 4b |
| Mobridge (2 mi NNW) | May 3 | May 16 | October 8 | September 25 | 157 days | 4b |
| Montrose8 mi N | May 3 | May 15 | October 4 | September 21 | 153 days | – |
| Murdo | May 3 | May 16 | October 9 | September 25 | 158 days | 5a |
| Rapid City Weather Office | May 3 | May 17 | October 8 | September 26 | 157 days | – |
| SissetonSisseton Municipal Airport | May 3 | May 16 | September 30 | September 17 | 149 days | 4b |
| Vermillion2 mi SE | May 3 | May 16 | October 3 | September 20 | 153 days | 5a |
| Watertown (2 mi S) | May 3 | May 14 | October 4 | September 22 | 153 days | – |
| White Lake | May 3 | May 17 | October 5 | September 21 | 153 days | 5a |
| Sisseton station | May 4 | May 17 | October 3 | September 22 | 151 days | 4b |
| Victor (4 mi N) | May 4 | May 17 | October 3 | September 21 | 152 days | 4b |
| Webster | May 4 | May 16 | October 6 | September 25 | 156 days | 4b |
| ClarkClark No2 | May 5 | May 17 | October 5 | September 24 | 152 days | – |
| Clark station | May 5 | May 18 | October 5 | September 24 | 153 days | 4b |
| De Smet | May 5 | May 20 | October 4 | September 23 | 151 days | 4b |
| Flandreau | May 5 | May 17 | October 1 | September 19 | 148 days | 4b |
| Howard | May 5 | May 18 | October 2 | September 19 | 149 days | 4b |
| Interior3 mi NE | May 5 | May 20 | October 7 | September 23 | 152 days | 5a |
| Madison2 mi SE | May 5 | May 18 | September 30 | September 18 | 148 days | 4b |
| Milbank | May 5 | May 18 | October 2 | September 20 | 150 days | – |
| MobridgeMobridge Municipal Airport | May 5 | May 20 | October 4 | September 21 | 150 days | 4b |
| Wilmot | May 5 | May 18 | October 1 | September 21 | 149 days | 4b |
| AndoverAndover #2 | May 6 | May 21 | October 4 | September 21 | 150 days | 4a |
| Astoria4 mi S | May 6 | May 20 | October 3 | September 20 | 150 days | – |
| Brookings2 mi NE | May 6 | May 19 | October 1 | September 17 | 145 days | 4b |
| CastlewoodCastlewood #2 | May 6 | May 20 | October 1 | September 19 | 145 days | – |
| Cedar Butte | May 6 | May 22 | October 4 | September 22 | 151 days | 5a |
| Conde | May 6 | May 20 | September 29 | September 16 | 144 days | – |
| Dupree (15 mi SSE) | May 6 | May 20 | October 2 | September 20 | 148 days | – |
| Faith station | May 6 | May 20 | October 5 | September 20 | 151 days | 5a |
| Gann Valley (4 mi NW) | May 6 | May 19 | October 1 | September 20 | 148 days | – |
| Gregory | May 6 | May 20 | October 3 | September 21 | 149 days | 5a |
| HuronHuron Regional Airport | May 6 | May 20 | October 2 | September 19 | 146 days | 4b |
| Kirley (6 mi N) | May 6 | May 21 | October 4 | September 21 | 148 days | 4b |
| Lake Sharpe Project | May 6 | May 20 | October 5 | September 23 | 152 days | – |
| Mission Ridge (5 mi NW) | May 6 | May 22 | October 7 | September 22 | 152 days | – |
| Oahe Dam | May 6 | May 19 | October 5 | September 23 | 152 days | – |
| PierrePierre Regional Airport | May 6 | May 21 | October 3 | September 20 | 148 days | 5a |
| Pierre (24 mi S) | May 6 | May 20 | October 7 | September 22 | 154 days | – |
| Winfred2 mi S | May 6 | May 17 | October 3 | September 22 | 151 days | – |
| Clear Lake | May 7 | May 21 | October 1 | September 19 | 146 days | 4b |
| Columbia8 mi N | May 7 | May 22 | September 29 | September 18 | 145 days | 4a |
| FaithFaith Municipal Airport | May 7 | May 20 | October 3 | September 19 | 147 days | 5a |
| Gann Valley3 mi NNE | May 7 | May 21 | October 1 | September 19 | 146 days | – |
| Gettysburg | May 7 | May 21 | October 2 | September 21 | 147 days | 4b |
| Oglala1 mi S | May 7 | May 21 | October 4 | September 21 | 149 days | – |
| Rauville (2 mi W) | May 7 | May 20 | September 28 | September 16 | 143 days | – |
| Roscoe | May 7 | May 20 | October 3 | September 19 | 148 days | 4b |
| Salem5 mi NE | May 7 | May 19 | September 29 | September 17 | 144 days | – |
| Turton | May 7 | May 22 | October 3 | September 21 | 149 days | – |
| WatertownWatertown Regional Airport | May 7 | May 20 | September 30 | September 19 | 145 days | 4b |
| Aberdeen (3 mi E) | May 8 | May 21 | September 29 | September 17 | 144 days | – |
| Alexandria | May 8 | May 21 | September 29 | September 17 | 143 days | 5a |
| Dupree | May 8 | May 22 | October 1 | September 17 | 144 days | 4b |
| Elm Springs (3 mi ESE) | May 8 | May 22 | October 3 | September 18 | 146 days | 5a |
| Fort Meade | May 8 | May 21 | October 3 | September 19 | 147 days | 5a |
| Hereford (12 mi SW) | May 8 | May 22 | October 3 | September 20 | 147 days | – |
| Ipswich | May 8 | May 22 | September 29 | September 17 | 143 days | 4b |
| Milesville (5 mi NE) | May 8 | May 22 | October 2 | September 17 | 147 days | 4b |
| Newell | May 8 | May 22 | October 1 | September 19 | 144 days | 4b |
| Onida4 mi NW | May 8 | May 22 | October 2 | September 19 | 147 days | 4b |
| Pollock | May 8 | May 21 | September 30 | September 18 | 143 days | 4a |
| Redfield | May 8 | May 21 | October 1 | September 19 | 145 days | – |
| Selby | May 8 | May 21 | October 1 | September 19 | 145 days | 4b |
| AberdeenAberdeen Regional Airport | May 9 | May 22 | September 26 | September 14 | 139 days | 4a |
| Forestburg4 mi NNE | May 9 | May 24 | September 28 | September 14 | 140 days | 4b |
| Leola | May 9 | May 21 | September 28 | September 17 | 141 days | – |
| Longvalley | May 9 | May 24 | October 1 | September 17 | 143 days | 5a |
| Manderson (3 mi NE) | May 9 | May 24 | October 4 | September 20 | 147 days | – |
| McIntosh (6 mi SE) | May 9 | May 24 | September 30 | September 19 | 143 days | 4b |
| Mission | May 9 | May 21 | October 1 | September 19 | 146 days | 5a |
| Aberdeen (35 mi WNW) | May 10 | May 22 | September 30 | September 19 | 143 days | – |
| Belle Fourche | May 10 | May 25 | September 30 | September 16 | 143 days | 4b |
| Bison | May 10 | May 24 | October 1 | September 16 | 144 days | 4b |
| BuffaloBuffalo Asos | May 10 | May 23 | October 1 | September 16 | 141 days | – |
| Castlewood station | May 10 | May 23 | September 27 | September 14 | 139 days | – |
| Faulkton1 mi NW | May 10 | May 25 | September 28 | September 15 | 139 days | 4b |
| Fort Pierre (17 mi WSW) | May 10 | May 25 | September 27 | September 13 | 138 days | 4a |
| Lemmon | May 10 | May 24 | September 30 | September 18 | 142 days | 4b |
| Rapid City (4 mi NW) | May 10 | May 25 | October 5 | September 20 | 147 days | – |
| Stephan2 mi NW | May 10 | May 24 | September 29 | September 16 | 140 days | 4b |
| Timber Lake | May 10 | May 23 | September 30 | September 17 | 141 days | 4b |
| Wasta | May 10 | May 25 | October 1 | September 14 | 141 days | 4b |
| Wood | May 10 | May 22 | October 1 | September 19 | 143 days | 5a |
| Glad Valley (2 mi W) | May 11 | May 24 | September 30 | September 16 | 140 days | 4b |
| Harrington | May 11 | May 24 | October 1 | September 18 | 143 days | 4b |
| Kyle2 mi E | May 11 | May 27 | October 1 | September 15 | 139 days | – |
| Mellette4 mi W | May 11 | May 23 | September 27 | September 15 | 137 days | 4a |
| Mission (14 mi S) | May 11 | May 25 | October 2 | September 21 | 145 days | – |
| PhilipPhilip Airport | May 11 | May 24 | September 30 | September 17 | 141 days | 4b |
| Zeona (10 mi SSW) | May 11 | May 27 | September 28 | September 12 | 137 days | – |
| Eureka | May 12 | May 25 | September 27 | September 14 | 137 days | 4b |
| Highmore1 mi W | May 12 | May 28 | October 1 | September 17 | 142 days | 4b |
| Kennebec | May 12 | May 26 | September 28 | September 15 | 137 days | 4b |
| McLaughlin | May 12 | May 25 | September 28 | September 16 | 137 days | – |
| Midland | May 12 | May 26 | September 28 | September 13 | 138 days | 4b |
| Presho7 mi NW | May 12 | May 28 | September 29 | September 16 | 140 days | – |
| Rapid CityRapid City Regional Airport | May 12 | May 26 | October 1 | September 16 | 139 days | 5a |
| Spearfish | May 12 | May 25 | October 2 | September 21 | 143 days | 5a |
| Britton | May 13 | May 27 | September 26 | September 14 | 135 days | 4a |
| Ladner (9 mi SW) | May 13 | May 25 | September 27 | September 11 | 135 days | – |
| Martin | May 13 | May 27 | October 2 | September 18 | 141 days | 5a |
| Maurine (12 mi SW) | May 13 | May 27 | September 28 | September 13 | 136 days | 4b |
| Highmore (23 mi N) | May 14 | May 25 | September 29 | September 16 | 138 days | – |
| Martin (8 mi E) | May 14 | May 28 | October 1 | September 16 | 139 days | – |
| Summit1 mi W | May 14 | May 28 | September 28 | September 13 | 136 days | 4a |
| Belle Fourche (22 mi NNW) | May 15 | May 28 | September 24 | September 9 | 130 days | – |
| Mount Rushmore National Memorial | May 15 | May 29 | October 1 | September 16 | 138 days | 5b |
| Oelrichs | May 15 | May 28 | September 30 | September 16 | 137 days | – |
| Oral | May 15 | May 28 | September 27 | September 11 | 133 days | 4b |
| Plainview (6 mi SSW) | May 15 | May 29 | September 27 | September 14 | 134 days | – |
| Redig (11 mi NE) | May 15 | May 27 | September 24 | September 9 | 131 days | 4b |
| Wind Cave | May 15 | May 30 | September 29 | September 13 | 133 days | 5a |
| Ardmore1 mi NW | May 16 | May 31 | September 23 | September 9 | 128 days | 4b |
| Cottonwood2 mi E | May 16 | May 29 | September 26 | September 13 | 132 days | 4b |
| Hot Springs | May 16 | May 31 | September 27 | September 12 | 133 days | 5a |
| Ludlow (3 mi SSE) | May 16 | May 29 | September 26 | September 9 | 131 days | 4b |
| Pine RidgePine Ridge Airport | May 16 | May 31 | September 27 | September 13 | 132 days | 4b |
| Red Owl | May 16 | May 27 | September 26 | September 11 | 131 days | 4b |
| Shadehill Reservoir | May 16 | May 29 | September 24 | September 9 | 131 days | – |
| Bear Ridge | May 17 | May 30 | September 27 | September 11 | 132 days | 5b |
| Camp Crook | May 17 | May 30 | September 24 | September 9 | 128 days | 4a |
| Harrold (12 mi SSW) | May 17 | May 31 | September 24 | September 10 | 129 days | – |
| Porcupine (11 mi N) | May 17 | June 1 | September 25 | September 10 | 130 days | – |
| Custer station | May 18 | June 1 | September 28 | September 10 | 129 days | 5a |
| Edgemont (23 mi NNW) | May 18 | June 1 | September 27 | September 14 | 130 days | – |
| Lead | May 18 | June 1 | September 29 | September 15 | 133 days | 5b |
| Ralph (1 mi N) | May 18 | May 31 | September 23 | September 8 | 126 days | – |
| Antelope Ranger Station | May 19 | June 2 | September 19 | September 3 | 121 days | – |
| Hoover | May 19 | May 31 | September 21 | September 6 | 122 days | – |
| Buffalo (13 mi ESE) | May 20 | June 2 | September 19 | September 3 | 120 days | – |
| Johnson Siding | May 20 | June 3 | September 25 | September 11 | 126 days | – |
| CusterCuster County Airport | May 23 | June 6 | September 24 | September 9 | 122 days | 5a |
| Edgemont | May 23 | June 7 | September 20 | September 6 | 117 days | 4b |
| Deadwood | May 24 | June 6 | September 25 | September 9 | 125 days | – |
| Pactola Dam | May 28 | June 11 | September 18 | September 4 | 112 days | 5a |
| Lodgepole (5 mi SW) | May 30 | June 13 | September 11 | August 28 | 103 days | – |
| Hill City | June 1 | June 19 | September 10 | August 29 | 102 days | 4b |
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities, growing-season length); station daily lows via ACIS (zone). Growing season: NOAA's median number of days between the last spring and first autumn 32°F night. Zone: the USDA's plant hardiness rule applied to the station's own 1991-2020 coldest nights.