Hosmer, SD 57448 Frost Dates
Hosmer, SD: when does the frost end?
Around 05/07 is the usual last spring frost, about 252 days away. Fall's first freeze usually shows up around 10/03, roughly 148 days after the last spring frost.
Zone 4b (-25 to -20°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 Hosmer, not a forecast for this year.
Stretching the season past the first frost
With roughly 5 weeks until Hosmer'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
05/07 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/24 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/20 and only about 1 year in 10 sees frost after that.
Hosmer against the rest of the dataset
About 148 days separate Hosmer's last and first frost, putting it 35,810 of 40,283 ZIP codes nationally. Within SD, it ranks 207 of 378.
Learn more
Before leaning on 57448's figures: the frost range explains how to read the range around Hosmer's dates instead of trusting one, while local microclimates explains what one yard in Hosmer can differ from the 57448 normal.