Herrick, SD 57538 Frost Dates
57538, near Herrick, SD: the frost window
Around 05/03 is the usual last spring frost, about 248 days away. Fall's first freeze usually shows up around 10/10, roughly 159 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Herrick 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
Herrick's growing season runs out in roughly 6 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 05/03 isn't a guarantee
05/03 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.
Herrick against the rest of the dataset
Herrick's growing season runs about 159 days, ranking 32,810 of 40,283 US ZIP codes measured here, longest to shortest. Within SD, it ranks 45 of 378.
Learn more
Two guides worth reading on 57538: the frost range, on how to read the range around Herrick's dates instead of trusting one, and local microclimates, on what one yard in Herrick can differ from the 57538 normal.