Bryant, SD 57221 Frost Dates
Frost dates for Bryant, SD, ZIP 57221
Typically, the last spring freeze lands around 05/05, roughly 250 days out. The first fall frost typically arrives around 10/04, about 151 frost-free days later.
The USDA Plant Hardiness Zone Map puts Bryant in Zone 4b (-25 to -20°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
Zone 4b around Bryant 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
05/05 is the middle of 30 years of NOAA records, not a promise. Plant by 04/22 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 Bryant compares
Bryant's growing season runs about 151 days, ranking 35,133 of 40,283 US ZIP codes measured here, longest to shortest. Within SD, it ranks 155 of 378.
Learn more
local microclimates explains what one yard in Bryant can differ from the 57221 normal, and zone vs. frost date explains why Zone 4b and Bryant's frost date answer different questions.