Chicago, IL 60078 Frost Dates
When can you plant in Chicago, IL?
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.
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 Chicago, not a forecast for this year.
What to do before the first frost
About 9 weeks of growing season left in Chicago before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Chicago's last frost
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 17,407 of 40,283 ZIP codes in this dataset. Within IL, it ranks 201 of 1,548.
Learn more
zone vs. frost date covers why Zone 5b and Chicago's frost date answer different questions. the frost range covers how to read the range around Chicago's dates instead of trusting one.