Yankton, SD 57078 Frost Dates
Frost dates for Yankton, SD, ZIP 57078
Around 04/27 is the usual last spring frost, about 242 days away. The first fall frost typically arrives around 10/11, about 164 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 Yankton, not a forecast for this year.
What to do before the first frost
Zone 5a around Yankton has about 6 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.
The actual range around Yankton's last frost
04/27 is the middle of 30 years of NOAA records, not a promise. Plant by 04/13 and you're betting against frost in roughly 9 years out of 10. 05/10 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Yankton compares
Yankton's growing season runs about 164 days, ranking 30,863 of 40,283 US ZIP codes measured here, longest to shortest. Within SD, it ranks 10 of 378.
Learn more
the frost range explains how to read the range around Yankton's dates instead of trusting one, and local microclimates explains what one yard in Yankton can differ from the 57078 normal.