Riverside, IL 60546 Frost Dates
60546, near Riverside, IL: the frost window
The last spring frost here typically falls around 04/11, about 226 days from today. Fall's first freeze usually shows up around 10/31, roughly 201 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 Riverside, not a forecast for this year.
Stretching the season past the first frost
Riverside'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.
Why 04/11 isn't a guarantee
04/11 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/30 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/27 and only about 1 year in 10 sees frost after that.
Riverside against the rest of the dataset
About 201 days separate Riverside's last and first frost, putting it 17,483 of 40,283 ZIP codes nationally. Within IL, it ranks 249 of 1,548.
Learn more
Two guides worth reading on 60546: local microclimates, on what one yard in Riverside can differ from the 60546 normal, and zone vs. frost date, on why Zone 6a and Riverside's frost date answer different questions.