Mukwonago, WI 53149 Frost Dates
When can you plant in Mukwonago, WI?
Typically, the last spring freeze lands around 05/01, roughly 246 days out. The first fall frost typically arrives around 10/13, about 162 frost-free days later.
Zone 5b (-15 to -10°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 Mukwonago, not a forecast for this year.
What to do before the first frost
About 7 weeks of growing season left in Mukwonago before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 05/01 isn't a guarantee
05/01 is the middle of 30 years of NOAA records, not a promise. Plant by 04/18 and you're betting against frost in roughly 9 years out of 10. 05/18 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Mukwonago compares
Mukwonago's growing season runs about 162 days, ranking 31,696 of 40,283 US ZIP codes measured here, longest to shortest. Within WI, it ranks 262 of 860.
Learn more
local microclimates covers what one yard in Mukwonago can differ from the 53149 normal. zone vs. frost date covers why Zone 5b and Mukwonago's frost date answer different questions.