Winnebago, IL 61079 Frost Dates
Frost dates for Winnebago, IL, ZIP 61079
Around 04/24 is the usual last spring frost, about 239 days away. The first fall frost typically arrives around 10/17, about 174 frost-free days later.
Winnebago sits in USDA Zone 5b (-15 to -10°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
What to do before the first frost
Zone 5b around Winnebago has about 7 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 04/24 isn't a guarantee
04/24 is the middle of 30 years of NOAA records, not a promise. Plant by 04/10 and you're betting against frost in roughly 9 years out of 10. 05/08 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Winnebago compares
At roughly 174 frost-free days, Winnebago places 27,476 of 40,283 ZIP codes in this dataset. Within IL, it ranks 1,233 of 1,548.
Learn more
local microclimates explains what one yard in Winnebago can differ from the 61079 normal, and zone vs. frost date explains why Zone 5b and Winnebago's frost date answer different questions.