Chillicothe, IL 61526 Frost Dates
61526, near Chillicothe, IL: the frost window
The last spring frost here typically falls around 04/22, about 237 days from today. Fall's first freeze usually shows up around 10/14, roughly 174 days after the last spring frost.
Zone 5b (-15 to -10°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Chillicothe, not a forecast for this year.
Stretching the season past the first frost
Chillicothe's growing season runs out in roughly 7 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around Chillicothe's last frost
04/22 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/08 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/06 and only about 1 year in 10 sees frost after that.
Chillicothe against the rest of the dataset
About 174 days separate Chillicothe's last and first frost, putting it 27,436 of 40,283 ZIP codes nationally. Within IL, it ranks 1,229 of 1,548.
Learn more
Two guides worth reading on 61526: local microclimates, on what one yard in Chillicothe can differ from the 61526 normal, and zone vs. frost date, on why Zone 5b and Chillicothe's frost date answer different questions.