Pierre, SD 57501 Frost Dates
Frost dates for Pierre, SD, ZIP 57501
Around 05/06 is the usual last spring frost, about 251 days away. The first fall frost typically arrives around 10/03, about 148 frost-free days later.
Pierre 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.
What to do before the first frost
Zone 4b around Pierre 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.
Why 05/06 isn't a guarantee
05/06 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. 05/21 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Pierre compares
At roughly 148 frost-free days, Pierre places 35,690 of 40,283 ZIP codes in this dataset. Within SD, it ranks 195 of 378.
Learn more
the frost range explains how to read the range around Pierre's dates instead of trusting one, and local microclimates explains what one yard in Pierre can differ from the 57501 normal.