Grant Park, IL 60940 Frost Dates
60940, near Grant Park, IL: the frost window
The last spring frost here typically falls around 04/29, about 244 days from today. Fall's first freeze usually shows up around 10/16, roughly 171 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Grant Park in Zone 5b (-15 to -10°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
Grant Park's growing season runs out in roughly 7 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 04/29 isn't a guarantee
04/29 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/14 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/14 and only about 1 year in 10 sees frost after that.
Grant Park against the rest of the dataset
At roughly 171 frost-free days, Grant Park places 28,713 of 40,283 ZIP codes in this dataset. Within IL, it ranks 1,377 of 1,548.
Learn more
Two guides worth reading on 60940: local microclimates, on what one yard in Grant Park can differ from the 60940 normal, and zone vs. frost date, on why Zone 5b and Grant Park's frost date answer different questions.