Chicago, IL 60622 Frost Dates
Chicago, IL: when does the frost end?
Around 04/10 is the usual last spring frost, about 225 days away. Fall's first freeze usually shows up around 11/05, roughly 208 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Chicago in Zone 6a (-10 to -5°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
With roughly 10 weeks until Chicago's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
04/10 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/29 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/25 and only about 1 year in 10 sees frost after that.
Chicago against the rest of the dataset
Chicago's growing season runs about 208 days, ranking 15,470 of 40,283 US ZIP codes measured here, longest to shortest. Within IL, it ranks 66 of 1,548.
Learn more
Before leaning on 60622's figures: the frost range explains how to read the range around Chicago's dates instead of trusting one, while local microclimates explains what one yard in Chicago can differ from the 60622 normal.