Rockford, IL 61103 Frost Dates
Frost dates for Rockford, IL, ZIP 61103
Typically, the last spring freeze lands around 04/24, roughly 239 days out. The first fall frost typically arrives around 10/17, about 174 frost-free days later.
Rockford sits in USDA Zone 5b (-15 to -10°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.
What to do before the first frost
Zone 5b around Rockford has about 7 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
How much risk comes with planting early here
04/24 is the middle of 30 years of NOAA records, not a promise. Plant by 04/10 and you're betting against frost in roughly 9 years out of 10. 05/08 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Rockford compares
At roughly 174 frost-free days, Rockford places 27,313 of 40,283 ZIP codes in this dataset. Within IL, it ranks 1,222 of 1,548.
Learn more
the frost range explains how to read the range around Rockford's dates instead of trusting one, and local microclimates explains what one yard in Rockford can differ from the 61103 normal.