Glendale Heights, IL 60139 Frost Dates
60139, near Glendale Heights, IL: the frost window
Typically, the last spring freeze lands around 04/27, roughly 242 days out. Fall's first freeze usually shows up around 10/17, roughly 173 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 Glendale Heights, not a forecast for this year.
Stretching the season past the first frost
Glendale Heights'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.
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.
Glendale Heights against the rest of the dataset
About 173 days separate Glendale Heights's last and first frost, putting it 27,783 of 40,283 ZIP codes nationally. Within IL, it ranks 1,303 of 1,548.
Learn more
Two guides worth reading on 60139: zone vs. frost date, on why Zone 5b and Glendale Heights's frost date answer different questions, and the frost range, on how to read the range around Glendale Heights's dates instead of trusting one.