Waterloo, IL 62256 Frost Dates
Waterloo, IL: when does the frost end?
Around 04/09 is the usual last spring frost, about 224 days away. Fall's first freeze usually shows up around 10/26, roughly 197 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Waterloo in Zone 7a (0 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 8 weeks until Waterloo's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 04/09 isn't a guarantee
04/09 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/25 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/25 and only about 1 year in 10 sees frost after that.
Waterloo against the rest of the dataset
At roughly 197 frost-free days, Waterloo places 18,646 of 40,283 ZIP codes in this dataset. Within IL, it ranks 314 of 1,548.
Learn more
Before leaning on 62256's figures: zone vs. frost date explains why Zone 7a and Waterloo's frost date answer different questions, while the frost range explains how to read the range around Waterloo's dates instead of trusting one.