Interior, SD 57577 Frost Dates
When can you plant in Interior, SD?
Around 05/09 is the usual last spring frost, about 254 days away. The first fall frost typically arrives around 10/01, about 143 frost-free days later.
Zone 5a (-20 to -15°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Interior, not a forecast for this year.
What to do before the first frost
About 5 weeks of growing season left in Interior before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Interior's last frost
05/09 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. 05/24 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Interior compares
At roughly 143 frost-free days, Interior places 36,680 of 40,283 ZIP codes in this dataset. Within SD, it ranks 279 of 378.
Learn more
the frost range covers how to read the range around Interior's dates instead of trusting one. local microclimates covers what one yard in Interior can differ from the 57577 normal.