Chicago, IL 60674 Frost Dates
Frost dates for Chicago, IL, ZIP 60674
Typically, the last spring freeze lands around 04/11, roughly 226 days out. The first fall frost typically arrives around 10/31, about 201 frost-free days later.
Chicago sits in USDA Zone 6b (-5 to 0°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 6b around Chicago has about 9 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 04/11 isn't a guarantee
04/11 is the middle of 30 years of NOAA records, not a promise. Plant by 03/30 and you're betting against frost in roughly 9 years out of 10. 04/27 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Chicago compares
About 201 days separate Chicago's last and first frost, putting it 17,425 of 40,283 ZIP codes nationally. Within IL, it ranks 219 of 1,548.
Learn more
the frost range explains how to read the range around Chicago's dates instead of trusting one, and local microclimates explains what one yard in Chicago can differ from the 60674 normal.