Chicago, IL 60677 Frost Dates
60677, near Chicago, IL: the frost window
The last spring frost here typically falls around 04/11, about 226 days from today. Fall's first freeze usually shows up around 10/31, roughly 201 days after the last spring frost.
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.
Stretching the season past the first frost
Chicago's growing season runs out in roughly 9 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around Chicago's last frost
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
At roughly 201 frost-free days, Chicago places 17,427 of 40,283 ZIP codes in this dataset. Within IL, it ranks 221 of 1,548.
Learn more
Two guides worth reading on 60677: local microclimates, on what one yard in Chicago can differ from the 60677 normal, and zone vs. frost date, on why Zone 6b and Chicago's frost date answer different questions.