Willow Lake, SD 57278 Frost Dates
When can you plant in Willow Lake, SD?
Typically, the last spring freeze lands around 05/05, roughly 250 days out. The first fall frost typically arrives around 10/04, about 151 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 Willow Lake, not a forecast for this year.
What to do before the first frost
About 5 weeks of growing season left in Willow Lake before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Willow Lake's last frost
05/05 is the middle of 30 years of NOAA records, not a promise. Plant by 04/22 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 Willow Lake compares
About 151 days separate Willow Lake's last and first frost, putting it 35,167 of 40,283 ZIP codes nationally. Within SD, it ranks 160 of 378.
Learn more
the frost range covers how to read the range around Willow Lake's dates instead of trusting one. local microclimates covers what one yard in Willow Lake can differ from the 57278 normal.