Wasta, SD 57767 Frost Dates
57767, near Wasta, SD: the frost window
Around 05/12 is the usual last spring frost, about 257 days away. Fall's first freeze usually shows up around 10/01, roughly 139 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Wasta 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
Wasta'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.
Why 05/12 isn't a guarantee
05/12 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/01 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/26 and only about 1 year in 10 sees frost after that.
Wasta against the rest of the dataset
At roughly 139 frost-free days, Wasta places 37,312 of 40,283 ZIP codes in this dataset. Within SD, it ranks 328 of 378.
Learn more
Two guides worth reading on 57767: zone vs. frost date, on why Zone 5a and Wasta's frost date answer different questions, and the frost range, on how to read the range around Wasta's dates instead of trusting one.