Deer Grove, IL 61243 Frost Dates
61243, near Deer Grove, IL: the frost window
Typically, the last spring freeze lands around 04/24, roughly 239 days out. Fall's first freeze usually shows up around 10/14, roughly 172 days after the last spring frost.
Deer Grove sits in USDA Zone 5b (-15 to -10°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
Deer Grove's growing season runs out in roughly 7 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 04/24 isn't a guarantee
04/24 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/10 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/09 and only about 1 year in 10 sees frost after that.
Deer Grove against the rest of the dataset
Deer Grove's growing season runs about 172 days, ranking 28,557 of 40,283 US ZIP codes measured here, longest to shortest. Within IL, it ranks 1,364 of 1,548.
Learn more
Two guides worth reading on 61243: zone vs. frost date, on why Zone 5b and Deer Grove's frost date answer different questions, and the frost range, on how to read the range around Deer Grove's dates instead of trusting one.