Roscoe, SD 57471 Frost Dates
Frost dates for Roscoe, SD, ZIP 57471
Typically, the last spring freeze lands around 05/07, roughly 252 days out. The first fall frost typically arrives around 10/03, about 148 frost-free days later.
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 Roscoe, not a forecast for this year.
What to do before the first frost
Zone 4b around Roscoe has about 5 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
How much risk comes with planting early here
05/07 is the middle of 30 years of NOAA records, not a promise. Plant by 04/24 and you're betting against frost in roughly 9 years out of 10. 05/20 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Roscoe compares
At roughly 148 frost-free days, Roscoe places 35,798 of 40,283 ZIP codes in this dataset. Within SD, it ranks 205 of 378.
Learn more
local microclimates explains what one yard in Roscoe can differ from the 57471 normal, and zone vs. frost date explains why Zone 4b and Roscoe's frost date answer different questions.