Fort Pierre, SD 57532 Frost Dates
When can you plant in Fort Pierre, SD?
Around 05/06 is the usual last spring frost, about 251 days away. The first fall frost typically arrives around 10/05, about 152 frost-free days later.
The USDA Plant Hardiness Zone Map puts Fort Pierre 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
About 5 weeks of growing season left in Fort Pierre before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 05/06 isn't a guarantee
05/06 is the middle of 30 years of NOAA records, not a promise. Plant by 04/23 and you're betting against frost in roughly 9 years out of 10. 05/19 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Fort Pierre compares
Fort Pierre's growing season runs about 152 days, ranking 34,779 of 40,283 US ZIP codes measured here, longest to shortest. Within SD, it ranks 133 of 378.
Learn more
zone vs. frost date covers why Zone 4b and Fort Pierre's frost date answer different questions. the frost range covers how to read the range around Fort Pierre's dates instead of trusting one.