Bartlett, IL 60103 Frost Dates
Bartlett, IL: when does the frost end?
Around 04/30 is the usual last spring frost, about 245 days away. Fall's first freeze usually shows up around 10/13, roughly 163 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Bartlett 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
With roughly 7 weeks until Bartlett's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 04/30 isn't a guarantee
04/30 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/17 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/16 and only about 1 year in 10 sees frost after that.
Bartlett against the rest of the dataset
At roughly 163 frost-free days, Bartlett places 31,316 of 40,283 ZIP codes in this dataset. Within IL, it ranks 1,514 of 1,548.
Learn more
Before leaning on 60103's figures: zone vs. frost date explains why Zone 5b and Bartlett's frost date answer different questions, while the frost range explains how to read the range around Bartlett's dates instead of trusting one.