Armour, SD 57313 Frost Dates
When can you plant in Armour, SD?
Around 04/29 is the usual last spring frost, about 244 days away. The first fall frost typically arrives around 10/09, about 164 frost-free days later.
The USDA Plant Hardiness Zone Map puts Armour in Zone 5a (-20 to -15°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 6 weeks of growing season left in Armour before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 04/29 isn't a guarantee
04/29 is the middle of 30 years of NOAA records, not a promise. Plant by 04/12 and you're betting against frost in roughly 9 years out of 10. 05/12 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Armour compares
About 164 days separate Armour's last and first frost, putting it 31,090 of 40,283 ZIP codes nationally. Within SD, it ranks 13 of 378.
Learn more
the frost range covers how to read the range around Armour's dates instead of trusting one. local microclimates covers what one yard in Armour can differ from the 57313 normal.