Harrold, SD 57536 Frost Dates
Harrold, SD: when does the frost end?
Typically, the last spring freeze lands around 05/12, roughly 257 days out. Fall's first freeze usually shows up around 10/01, roughly 142 days after the last spring frost.
Harrold 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 Harrold's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
05/12 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/28 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/28 and only about 1 year in 10 sees frost after that.
Harrold against the rest of the dataset
About 142 days separate Harrold's last and first frost, putting it 36,843 of 40,283 ZIP codes nationally. Within SD, it ranks 287 of 378.
Learn more
Before leaning on 57536's figures: the frost range explains how to read the range around Harrold's dates instead of trusting one, while local microclimates explains what one yard in Harrold can differ from the 57536 normal.