Chatham, IL 62536 Frost Dates
62536, near Chatham, IL: the frost window
The last spring frost here typically falls around 04/07, about 222 days from today. Fall's first freeze usually shows up around 10/29, roughly 205 days after the last spring frost.
Chatham sits in USDA Zone 6a (-10 to -5°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
Chatham's growing season runs out in roughly 9 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
How much risk comes with planting early here
04/07 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/22 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/21 and only about 1 year in 10 sees frost after that.
Chatham against the rest of the dataset
At roughly 205 frost-free days, Chatham places 16,197 of 40,283 ZIP codes in this dataset. Within IL, it ranks 109 of 1,548.
Learn more
Two guides worth reading on 62536: local microclimates, on what one yard in Chatham can differ from the 62536 normal, and zone vs. frost date, on why Zone 6a and Chatham's frost date answer different questions.