Viborg, SD 57070 Frost Dates
57070, near Viborg, SD: the frost window
Around 05/02 is the usual last spring frost, about 247 days away. Fall's first freeze usually shows up around 10/01, roughly 151 days after the last spring frost.
Zone 5a (-20 to -15°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Viborg, not a forecast for this year.
Stretching the season past the first frost
Viborg'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
05/02 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/19 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/15 and only about 1 year in 10 sees frost after that.
Viborg against the rest of the dataset
About 151 days separate Viborg's last and first frost, putting it 35,105 of 40,283 ZIP codes nationally. Within SD, it ranks 151 of 378.
Learn more
Two guides worth reading on 57070: the frost range, on how to read the range around Viborg's dates instead of trusting one, and local microclimates, on what one yard in Viborg can differ from the 57070 normal.