Bourbonnais, IL 60914 Frost Dates
60914, near Bourbonnais, IL: the frost window
Typically, the last spring freeze lands around 04/19, roughly 234 days out. Fall's first freeze usually shows up around 10/24, roughly 188 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Bourbonnais 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
Bourbonnais's growing season runs out in roughly 8 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 04/19 isn't a guarantee
04/19 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/05 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/03 and only about 1 year in 10 sees frost after that.
Bourbonnais against the rest of the dataset
Bourbonnais's growing season runs about 188 days, ranking 21,882 of 40,283 US ZIP codes measured here, longest to shortest. Within IL, it ranks 668 of 1,548.
Learn more
Two guides worth reading on 60914: the frost range, on how to read the range around Bourbonnais's dates instead of trusting one, and local microclimates, on what one yard in Bourbonnais can differ from the 60914 normal.