New Underwood, SD 57761 Frost Dates
57761, near New Underwood, SD: the frost window
Typically, the last spring freeze lands around 05/12, roughly 257 days out. Fall's first freeze usually shows up around 10/01, roughly 139 days after the last spring frost.
New Underwood sits in USDA Zone 5a (-20 to -15°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
New Underwood'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.
The actual range around New Underwood's last frost
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.
New Underwood against the rest of the dataset
At roughly 139 frost-free days, New Underwood places 37,261 of 40,283 ZIP codes in this dataset. Within SD, it ranks 319 of 378.
Learn more
Two guides worth reading on 57761: zone vs. frost date, on why Zone 5a and New Underwood's frost date answer different questions, and the frost range, on how to read the range around New Underwood's dates instead of trusting one.