Lake Forest, IL 60045 Frost Dates
60045, near Lake Forest, IL: the frost window
Typically, the last spring freeze lands around 04/30, roughly 245 days out. Fall's first freeze usually shows up around 10/19, roughly 170 days after the last spring frost.
Lake Forest sits in USDA Zone 6a (-10 to -5°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
Lake Forest'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.
The actual range around Lake Forest's last frost
04/30 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/15 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.
Lake Forest against the rest of the dataset
About 170 days separate Lake Forest's last and first frost, putting it 28,920 of 40,283 ZIP codes nationally. Within IL, it ranks 1,388 of 1,548.
Learn more
Two guides worth reading on 60045: zone vs. frost date, on why Zone 6a and Lake Forest's frost date answer different questions, and the frost range, on how to read the range around Lake Forest's dates instead of trusting one.