Edgemont, SD 57735 Frost Dates
57735, near Edgemont, SD: the frost window
Around 05/23 is the usual last spring frost, about 268 days away. Fall's first freeze usually shows up around 09/20, roughly 117 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Edgemont in Zone 4b (-25 to -20°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
Edgemont's growing season runs out in roughly 3 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 Edgemont's last frost
05/23 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/11 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/07 and only about 1 year in 10 sees frost after that.
Edgemont against the rest of the dataset
At roughly 117 frost-free days, Edgemont places 39,254 of 40,283 ZIP codes in this dataset. Within SD, it ranks 375 of 378.
Learn more
Two guides worth reading on 57735: local microclimates, on what one yard in Edgemont can differ from the 57735 normal, and zone vs. frost date, on why Zone 4b and Edgemont's frost date answer different questions.