Chicago, IL 60685 Frost Dates
Frost dates for Chicago, IL, ZIP 60685
Around 04/11 is the usual last spring frost, about 226 days away. The first fall frost typically arrives around 10/31, about 201 frost-free days later.
The USDA Plant Hardiness Zone Map puts Chicago in Zone 6b (-5 to 0°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's 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.
How much risk comes with planting early here
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
At roughly 201 frost-free days, Chicago places 17,432 of 40,283 ZIP codes in this dataset. Within IL, it ranks 226 of 1,548.
Learn more
zone vs. frost date explains why Zone 6b and Chicago's frost date answer different questions, and the frost range explains how to read the range around Chicago's dates instead of trusting one.