New Underwood, SD 57737 Frost Dates
When can you plant in New Underwood, SD?
The last spring frost here typically falls around 05/15, about 260 days from today. The first fall frost typically arrives around 09/27, about 134 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 New Underwood, not a forecast for this year.
What to do before the first frost
About 4 weeks of growing season left in New Underwood before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 05/15 isn't a guarantee
05/15 is the middle of 30 years of NOAA records, not a promise. Plant by 05/03 and you're betting against frost in roughly 9 years out of 10. 05/29 is the safer bet, historically only a 1-in-10 chance of frost that late.
How New Underwood compares
About 134 days separate New Underwood's last and first frost, putting it 38,006 of 40,283 ZIP codes nationally. Within SD, it ranks 353 of 378.
Learn more
zone vs. frost date covers why Zone 4b and New Underwood's frost date answer different questions. the frost range covers how to read the range around New Underwood's dates instead of trusting one.