Herscher, IL 60941 Frost Dates
60941, near Herscher, IL: the frost window
The last spring frost here typically falls around 04/19, about 234 days from today. Fall's first freeze usually shows up around 10/24, roughly 188 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 Herscher, not a forecast for this year.
Stretching the season past the first frost
Herscher'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.
Why 04/19 isn't a guarantee
04/19 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/05 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/03 and only about 1 year in 10 sees frost after that.
Herscher against the rest of the dataset
At roughly 188 frost-free days, Herscher places 22,091 of 40,283 ZIP codes in this dataset. Within IL, it ranks 689 of 1,548.
Learn more
Two guides worth reading on 60941: local microclimates, on what one yard in Herscher can differ from the 60941 normal, and zone vs. frost date, on why Zone 5b and Herscher's frost date answer different questions.