Carbon Cliff, IL 61239 Frost Dates
When can you plant in Carbon Cliff, IL?
Typically, the last spring freeze lands around 04/24, roughly 239 days out. The first fall frost typically arrives around 10/18, about 176 frost-free days later.
The USDA Plant Hardiness Zone Map puts Carbon Cliff in Zone 5b (-15 to -10°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
About 7 weeks of growing season left in Carbon Cliff before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
How much risk comes with planting early here
04/24 is the middle of 30 years of NOAA records, not a promise. Plant by 04/09 and you're betting against frost in roughly 9 years out of 10. 05/09 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Carbon Cliff compares
About 176 days separate Carbon Cliff's last and first frost, putting it 26,491 of 40,283 ZIP codes nationally. Within IL, it ranks 1,177 of 1,548.
Learn more
zone vs. frost date covers why Zone 5b and Carbon Cliff's frost date answer different questions. the frost range covers how to read the range around Carbon Cliff's dates instead of trusting one.