Wanamingo, MN 55983 Frost Dates
Frost dates for Wanamingo, MN, ZIP 55983
Typically, the last spring freeze lands around 05/09, roughly 254 days out. The first fall frost typically arrives around 09/30, about 144 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 Wanamingo, not a forecast for this year.
What to do before the first frost
Zone 4b around Wanamingo 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.
Why 05/09 isn't a guarantee
05/09 is the middle of 30 years of NOAA records, not a promise. Plant by 04/24 and you're betting against frost in roughly 9 years out of 10. 05/22 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Wanamingo compares
Wanamingo's growing season runs about 144 days, ranking 36,402 of 40,283 US ZIP codes measured here, longest to shortest. Within MN, it ranks 658 of 943.
Learn more
zone vs. frost date explains why Zone 4b and Wanamingo's frost date answer different questions, and the frost range explains how to read the range around Wanamingo's dates instead of trusting one.