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Frost Dates and Planting Windows in South Dakota

The 32°F frost dates at the 166 weather stations in South Dakota with NOAA's 1991–2020 Climate Normals, and the planting windows they give. These are long-term statistics, not a forecast. For the dates at the station nearest you, enter your ZIP code.

The planner uses the weather station nearest your ZIP code.

Frost dates across South Dakota

Each risk level uses a date with a set chance of frost. In spring, it's the chance of a 32°F frost on or after the last-frost date. In fall, it's the chance of the first 32°F frost on or before the first-frost date. At the Typical level (30%), the last frost ranges from May 2 to June 7 across the state, and the first frost from September 5 to October 7.

32°F frost dates: earliest and latest among 166 stations, by risk level
Risk levelEarliest last frostLatest last frostEarliest first frostLatest first frost
Conservative (10%)May 9SIOUX FALLS WFO AP, SD USJune 19HILL CITY, SD USAugust 28LODGEPOLE 5SW, SD USSeptember 302 stations
Typical (30%)May 24 stationsJune 7HILL CITY, SD USSeptember 52 stationsOctober 72 stations
Aggressive (50%)April 26SIOUX FALLS WFO AP, SD USJune 1HILL CITY, SD USSeptember 10HILL CITY, SD USOctober 133 stations

Growing season length

The growing season is the stretch between the last spring frost and the first fall frost at 32°F. NOAA gives it as a length with a chance of being at least that long. Each risk level uses the length with that chance of a shorter season, so Conservative shows the shortest lengths.

Growing season at 32°F: shortest and longest among 166 stations
Risk levelShortestLongest
Conservative (90% chance of at least this long)76 daysHILL CITY, SD US149 days3 stations
Typical (70% chance of at least this long)92 daysHILL CITY, SD US161 daysPICKSTOWN 4SSW, SD US
Aggressive (50% chance of at least this long)102 daysHILL CITY, SD US169 daysSIOUX FALLS WFO AP, SD US
Number of stations by growing season length, Typical (70% chance of at least this long)
Growing seasonStations
80–99 days2
100–119 days9
120–139 days86
140–159 days67
160–179 days2

Planting windows across South Dakota

For each crop, the earliest start and the latest end of its Typical windows among the stations. A window at any one station is shorter and falls inside this span. Transplant dates are for seedlings. A fall window is left out at stations where it would start on or before the last day of the spring window, so some rows cover fewer stations.

Typical planting windows (30% frost dates): earliest start and latest end among stations
Crop and taskEarliest startLatest endStations
Basil: Transplant outdoorsMay 16June 21166 of 166
Bean: Sow outdoorsMay 2June 7166 of 166
Beet: Sow outdoorsApril 4June 7166 of 166
Beet: Sow for fallJune 13August 18166 of 166
Broccoli: Transplant outdoorsApril 4May 24166 of 166
Broccoli: Transplant for fallJune 3August 18166 of 166
Brussels sprouts: Transplant outdoorsApril 4May 24166 of 166
Brussels sprouts: Transplant for fallMay 21August 28164 of 166
Cabbage: Transplant outdoorsApril 4May 24166 of 166
Cabbage: Transplant for fallMay 29August 18166 of 166
Cantaloupe: Transplant outdoorsMay 16June 21166 of 166
Cantaloupe: Sow outdoorsMay 16June 21166 of 166
Carrot: Sow outdoorsApril 4June 7166 of 166
Carrot: Sow for fallJune 10August 8164 of 166
Cucumber: Transplant outdoorsMay 9June 14166 of 166
Cucumber: Sow outdoorsMay 2June 7166 of 166
Eggplant: Transplant outdoorsMay 16June 21166 of 166
Garlic: Plant for fallSeptember 5October 21166 of 166
Lettuce: Transplant outdoorsApril 4May 24166 of 166
Lettuce: Sow outdoorsApril 4May 24166 of 166
Lettuce: Sow for fallJune 3August 28166 of 166
Onion: Transplant or plant setsApril 4May 24166 of 166
Peas: Sow outdoorsApril 4May 24166 of 166
Peas: Sow for fallJune 11August 18166 of 166
Pepper: Transplant outdoorsMay 16June 21166 of 166
Potato: Plant seed potatoesApril 4June 7166 of 166
Pumpkin: Sow outdoorsMay 16June 21166 of 166
Radish: Sow outdoorsApril 4May 24166 of 166
Radish: Sow for fallJuly 18September 17166 of 166
Spinach: Transplant outdoorsApril 4May 24166 of 166
Spinach: Sow outdoorsApril 4May 24166 of 166
Spinach: Sow for fallJune 23August 31166 of 166
Summer squash: Transplant outdoorsMay 9June 14166 of 166
Summer squash: Sow outdoorsMay 2June 7166 of 166
Sweet corn: Sow outdoorsMay 2June 7166 of 166
Sweet potato: Plant slipsMay 9June 21166 of 166
Tomato: Transplant outdoorsMay 16June 21166 of 166
Turnip: Sow outdoorsApril 4May 24166 of 166
Turnip: Sow for fallJune 23August 28166 of 166
Watermelon: Transplant outdoorsMay 16June 21166 of 166
Watermelon: Sow outdoorsMay 16June 21166 of 166

Weather stations in South Dakota

Every station in South Dakota with NOAA frost-date normals, with its Typical 32°F frost dates and growing season. 1 of them have no 32°F frost dates.

Data sources

NOAA U.S. Climate Normals, frost dates, 1991–2020 normals, version 1.0.1
Files: us-climate-normals_1991-2020_v1.0.1_annualseasonal_multivariate_by-station_c20230404.tar.gz, inventory_30yr.txt from NOAA NCEI. Retrieved October 10, 2026.