Henry, SD 57243 Frost Dates
Frost dates for Henry, SD, ZIP 57243
The last spring frost here typically falls around 05/07, about 252 days from today. The first fall frost typically arrives around 09/30, about 145 frost-free days later.
The USDA Plant Hardiness Zone Map puts Henry 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 Henry 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 04/26 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 Henry compares
At roughly 145 frost-free days, Henry places 36,277 of 40,283 ZIP codes in this dataset. Within SD, it ranks 244 of 378.
Learn more
the frost range explains how to read the range around Henry's dates instead of trusting one, and local microclimates explains what one yard in Henry can differ from the 57243 normal.