Vienna, SD 57271 Frost Dates
Frost dates for Vienna, SD, ZIP 57271
Around 05/07 is the usual last spring frost, about 252 days away. The first fall frost typically arrives around 09/30, about 145 frost-free days later.
Zone 4b (-25 to -20°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 Vienna, not a forecast for this year.
What to do before the first frost
Zone 4b around Vienna 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.
The actual range around Vienna's last frost
05/07 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. 05/20 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Vienna compares
About 145 days separate Vienna's last and first frost, putting it 36,316 of 40,283 ZIP codes nationally. Within SD, it ranks 253 of 378.
Learn more
local microclimates explains what one yard in Vienna can differ from the 57271 normal, and zone vs. frost date explains why Zone 4b and Vienna's frost date answer different questions.