Round Lake Heights, IL 60041 Frost Dates
60041, near Round Lake Heights, IL: the frost window
Around 04/24 is the usual last spring frost, about 239 days away. Fall's first freeze usually shows up around 10/23, roughly 180 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Round Lake Heights in Zone 5b (-15 to -10°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
Round Lake 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 04/24 isn't a guarantee
04/24 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/11 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.
Round Lake Heights against the rest of the dataset
At roughly 180 frost-free days, Round Lake Heights places 24,877 of 40,283 ZIP codes in this dataset. Within IL, it ranks 960 of 1,548.
Learn more
Two guides worth reading on 60041: the frost range, on how to read the range around Round Lake Heights's dates instead of trusting one, and local microclimates, on what one yard in Round Lake Heights can differ from the 60041 normal.