Harristown, IL 62522 Frost Dates
62522, near Harristown, IL: the frost window
Around 04/14 is the usual last spring frost, about 229 days away. Fall's first freeze usually shows up around 10/24, roughly 192 days after the last spring frost.
Zone 6a (-10 to -5°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 Harristown, not a forecast for this year.
Stretching the season past the first frost
Harristown's growing season runs out in roughly 8 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 Harristown's last frost
04/14 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/01 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/01 and only about 1 year in 10 sees frost after that.
Harristown against the rest of the dataset
At roughly 192 frost-free days, Harristown places 20,448 of 40,283 ZIP codes in this dataset. Within IL, it ranks 424 of 1,548.
Learn more
Two guides worth reading on 62522: the frost range, on how to read the range around Harristown's dates instead of trusting one, and local microclimates, on what one yard in Harristown can differ from the 62522 normal.