Highland, IL 62249 Frost Dates
62249, near Highland, IL: the frost window
Typically, the last spring freeze lands around 04/12, roughly 227 days out. Fall's first freeze usually shows up around 10/20, roughly 189 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Highland in Zone 6b (-5 to 0°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
Highland'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 04/12 isn't a guarantee
04/12 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/28 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/28 and only about 1 year in 10 sees frost after that.
Highland against the rest of the dataset
About 189 days separate Highland's last and first frost, putting it 21,472 of 40,283 ZIP codes nationally. Within IL, it ranks 576 of 1,548.
Learn more
Two guides worth reading on 62249: local microclimates, on what one yard in Highland can differ from the 62249 normal, and zone vs. frost date, on why Zone 6b and Highland's frost date answer different questions.