Bonnie, IL 62816 Frost Dates
Bonnie, IL: when does the frost end?
Around 04/04 is the usual last spring frost, about 219 days away. Fall's first freeze usually shows up around 10/27, roughly 204 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Bonnie in Zone 6b (-5 to 0°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 Bonnie's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 04/04 isn't a guarantee
04/04 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/21 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/19 and only about 1 year in 10 sees frost after that.
Bonnie against the rest of the dataset
About 204 days separate Bonnie's last and first frost, putting it 16,747 of 40,283 ZIP codes nationally. Within IL, it ranks 143 of 1,548.
Learn more
Before leaning on 62816's figures: zone vs. frost date explains why Zone 6b and Bonnie's frost date answer different questions, while the frost range explains how to read the range around Bonnie's dates instead of trusting one.