Sioux Falls, SD 57108 Frost Dates
57108, near Sioux Falls, SD: the frost window
Typically, the last spring freeze lands around 05/01, roughly 246 days out. Fall's first freeze usually shows up around 10/06, roughly 157 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Sioux Falls in Zone 5a (-20 to -15°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
Sioux Falls's growing season runs out in roughly 6 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around Sioux Falls's last frost
05/01 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/18 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/14 and only about 1 year in 10 sees frost after that.
Sioux Falls against the rest of the dataset
Sioux Falls's growing season runs about 157 days, ranking 33,189 of 40,283 US ZIP codes measured here, longest to shortest. Within SD, it ranks 63 of 378.
Learn more
Two guides worth reading on 57108: local microclimates, on what one yard in Sioux Falls can differ from the 57108 normal, and zone vs. frost date, on why Zone 5a and Sioux Falls's frost date answer different questions.