Naperville, IL 60565 Frost Dates
Naperville, IL: when does the frost end?
Typically, the last spring freeze lands around 04/27, roughly 242 days out. Fall's first freeze usually shows up around 10/17, roughly 173 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Naperville 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 7 weeks until Naperville's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Naperville's last frost
04/27 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/12 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.
Naperville against the rest of the dataset
At roughly 173 frost-free days, Naperville places 27,670 of 40,283 ZIP codes in this dataset. Within IL, it ranks 1,280 of 1,548.
Learn more
Before leaning on 60565's figures: local microclimates explains what one yard in Naperville can differ from the 60565 normal, while zone vs. frost date explains why Zone 6a and Naperville's frost date answer different questions.