Huron, SD 57399 Frost Dates
Frost dates for Huron, SD, ZIP 57399
Around 05/06 is the usual last spring frost, about 251 days away. The first fall frost typically arrives around 10/02, about 146 frost-free days later.
The USDA Plant Hardiness Zone Map puts Huron 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 Huron 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
05/06 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. 05/20 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Huron compares
At roughly 146 frost-free days, Huron places 36,033 of 40,283 ZIP codes in this dataset. Within SD, it ranks 214 of 378.
Learn more
zone vs. frost date explains why Zone 4b and Huron's frost date answer different questions, and the frost range explains how to read the range around Huron's dates instead of trusting one.