Rosemont, IL 60018 Frost Dates
Rosemont, IL: when does the frost end?
Typically, the last spring freeze lands around 04/16, roughly 231 days out. Fall's first freeze usually shows up around 10/28, roughly 193 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Rosemont 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 9 weeks until Rosemont's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 04/16 isn't a guarantee
04/16 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/03 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/01 and only about 1 year in 10 sees frost after that.
Rosemont against the rest of the dataset
About 193 days separate Rosemont's last and first frost, putting it 19,915 of 40,283 ZIP codes nationally. Within IL, it ranks 399 of 1,548.
Learn more
Before leaning on 60018's figures: zone vs. frost date explains why Zone 6a and Rosemont's frost date answer different questions, while the frost range explains how to read the range around Rosemont's dates instead of trusting one.