Flandreau, SD 57028 Frost Dates
Flandreau, SD: when does the frost end?
Typically, the last spring freeze lands around 05/04, roughly 249 days out. Fall's first freeze usually shows up around 10/02, roughly 152 days after the last spring frost.
Flandreau 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
With roughly 5 weeks until Flandreau's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 05/04 isn't a guarantee
05/04 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/21 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/19 and only about 1 year in 10 sees frost after that.
Flandreau against the rest of the dataset
Flandreau's growing season runs about 152 days, ranking 34,774 of 40,283 US ZIP codes measured here, longest to shortest. Within SD, it ranks 132 of 378.
Learn more
Before leaning on 57028's figures: local microclimates explains what one yard in Flandreau can differ from the 57028 normal, while zone vs. frost date explains why Zone 4b and Flandreau's frost date answer different questions.