Amboy, IL 61331 Frost Dates
61331, near Amboy, IL: the frost window
The last spring frost here typically falls around 04/27, about 242 days from today. Fall's first freeze usually shows up around 10/12, roughly 167 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 Amboy, not a forecast for this year.
Stretching the season past the first frost
Amboy's growing season runs out in roughly 6 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
04/27 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/12 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/14 and only about 1 year in 10 sees frost after that.
Amboy against the rest of the dataset
At roughly 167 frost-free days, Amboy places 30,018 of 40,283 ZIP codes in this dataset. Within IL, it ranks 1,456 of 1,548.
Learn more
Two guides worth reading on 61331: local microclimates, on what one yard in Amboy can differ from the 61331 normal, and zone vs. frost date, on why Zone 5b and Amboy's frost date answer different questions.