Rockford, IL 61104 Frost Dates
Rockford, IL: when does the frost end?
Typically, the last spring freeze lands around 04/24, roughly 239 days out. Fall's first freeze usually shows up around 10/17, roughly 174 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Rockford 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
With roughly 7 weeks until Rockford's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
04/24 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/10 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/08 and only about 1 year in 10 sees frost after that.
Rockford against the rest of the dataset
Rockford's growing season runs about 174 days, ranking 27,314 of 40,283 US ZIP codes measured here, longest to shortest. Within IL, it ranks 1,223 of 1,548.
Learn more
Before leaning on 61104's figures: zone vs. frost date explains why Zone 5b and Rockford's frost date answer different questions, while the frost range explains how to read the range around Rockford's dates instead of trusting one.