Greenfield, IL 62098 Frost Dates
62098, near Greenfield, IL: the frost window
The last spring frost here typically falls around 04/13, about 228 days from today. Fall's first freeze usually shows up around 10/22, roughly 190 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Greenfield in Zone 6a (-10 to -5°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
Greenfield'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 04/13 isn't a guarantee
04/13 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/30 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.
Greenfield against the rest of the dataset
Greenfield's growing season runs about 190 days, ranking 21,235 of 40,283 US ZIP codes measured here, longest to shortest. Within IL, it ranks 521 of 1,548.
Learn more
Two guides worth reading on 62098: local microclimates, on what one yard in Greenfield can differ from the 62098 normal, and zone vs. frost date, on why Zone 6a and Greenfield's frost date answer different questions.