Marvin, SD 57251 Frost Dates
Frost dates for Marvin, SD, ZIP 57251
The last spring frost here typically falls around 05/14, about 259 days from today. The first fall frost typically arrives around 09/28, about 136 frost-free days later.
Marvin sits in USDA Zone 4b (-25 to -20°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
What to do before the first frost
Zone 4b around Marvin has about 4 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
05/14 is the middle of 30 years of NOAA records, not a promise. Plant by 05/01 and you're betting against frost in roughly 9 years out of 10. 05/28 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Marvin compares
At roughly 136 frost-free days, Marvin places 37,823 of 40,283 ZIP codes in this dataset. Within SD, it ranks 352 of 378.
Learn more
zone vs. frost date explains why Zone 4b and Marvin's frost date answer different questions, and the frost range explains how to read the range around Marvin's dates instead of trusting one.