Donovan, IL 60931 Frost Dates
60931, near Donovan, 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 10/16, roughly 174 days after the last spring frost.
Donovan 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
Donovan'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 05/10 and only about 1 year in 10 sees frost after that.
Donovan against the rest of the dataset
At roughly 174 frost-free days, Donovan places 27,632 of 40,283 ZIP codes in this dataset. Within IL, it ranks 1,275 of 1,548.
Learn more
Two guides worth reading on 60931: zone vs. frost date, on why Zone 5b and Donovan's frost date answer different questions, and the frost range, on how to read the range around Donovan's dates instead of trusting one.