Herreid, SD 57632 Frost Dates
57632, near Herreid, SD: the frost window
Typically, the last spring freeze lands around 05/08, roughly 253 days out. Fall's first freeze usually shows up around 10/01, roughly 145 days after the last spring frost.
Herreid sits in USDA Zone 4b (-25 to -20°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
Herreid's growing season runs out in roughly 5 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
How much risk comes with planting early here
05/08 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/26 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/21 and only about 1 year in 10 sees frost after that.
Herreid against the rest of the dataset
At roughly 145 frost-free days, Herreid places 36,269 of 40,283 ZIP codes in this dataset. Within SD, it ranks 242 of 378.
Learn more
Two guides worth reading on 57632: zone vs. frost date, on why Zone 4b and Herreid's frost date answer different questions, and the frost range, on how to read the range around Herreid's dates instead of trusting one.