Arrowsmith, IL 61722 Frost Dates
61722, near Arrowsmith, IL: the frost window
The last spring frost here typically falls around 04/21, about 236 days from today. Fall's first freeze usually shows up around 10/17, roughly 178 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Arrowsmith 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
Arrowsmith'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.
Why 04/21 isn't a guarantee
04/21 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/10 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/05 and only about 1 year in 10 sees frost after that.
Arrowsmith against the rest of the dataset
At roughly 178 frost-free days, Arrowsmith places 25,912 of 40,283 ZIP codes in this dataset. Within IL, it ranks 1,108 of 1,548.
Learn more
Two guides worth reading on 61722: zone vs. frost date, on why Zone 6a and Arrowsmith's frost date answer different questions, and the frost range, on how to read the range around Arrowsmith's dates instead of trusting one.