Montrose, SD 57048 Frost Dates
Frost dates for Montrose, SD, ZIP 57048
Typically, the last spring freeze lands around 05/03, roughly 248 days out. The first fall frost typically arrives around 10/04, about 153 frost-free days later.
The USDA Plant Hardiness Zone Map puts Montrose 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
Zone 5a around Montrose 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 05/03 isn't a guarantee
05/03 is the middle of 30 years of NOAA records, not a promise. Plant by 04/20 and you're betting against frost in roughly 9 years out of 10. 05/15 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Montrose compares
About 153 days separate Montrose's last and first frost, putting it 34,601 of 40,283 ZIP codes nationally. Within SD, it ranks 120 of 378.
Learn more
zone vs. frost date explains why Zone 5a and Montrose's frost date answer different questions, and the frost range explains how to read the range around Montrose's dates instead of trusting one.