Peoria Heights, IL 61639 Frost Dates
61639, near Peoria Heights, IL: the frost window
Typically, the last spring freeze lands around 04/16, roughly 231 days out. Fall's first freeze usually shows up around 10/23, roughly 189 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 Peoria Heights, not a forecast for this year.
Stretching the season past the first frost
Peoria Heights'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 04/16 isn't a guarantee
04/16 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/02 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/04 and only about 1 year in 10 sees frost after that.
Peoria Heights against the rest of the dataset
Peoria Heights's growing season runs about 189 days, ranking 21,536 of 40,283 US ZIP codes measured here, longest to shortest. Within IL, it ranks 588 of 1,548.
Learn more
Two guides worth reading on 61639: local microclimates, on what one yard in Peoria Heights can differ from the 61639 normal, and zone vs. frost date, on why Zone 6a and Peoria Heights's frost date answer different questions.