Chicago, IL 60680 Frost Dates
Chicago, IL: when does the frost end?
Around 04/11 is the usual last spring frost, about 226 days away. Fall's first freeze usually shows up around 10/31, roughly 201 days after the last spring frost.
Zone 6b (-5 to 0°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.
Stretching the season past the first frost
With roughly 9 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
04/11 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/30 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/27 and only about 1 year in 10 sees frost after that.
Chicago against the rest of the dataset
About 201 days separate Chicago's last and first frost, putting it 17,429 of 40,283 ZIP codes nationally. Within IL, it ranks 223 of 1,548.
Learn more
Before leaning on 60680'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 60680 normal.