Sterling, IL 61037 Frost Dates
Frost dates for Sterling, IL, ZIP 61037
Typically, the last spring freeze lands around 04/26, roughly 241 days out. The first fall frost typically arrives around 10/13, about 167 frost-free days later.
The USDA Plant Hardiness Zone Map puts Sterling 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
Zone 5b around Sterling 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.
Why 04/26 isn't a guarantee
04/26 is the middle of 30 years of NOAA records, not a promise. Plant by 04/13 and you're betting against frost in roughly 9 years out of 10. 05/11 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Sterling compares
About 167 days separate Sterling's last and first frost, putting it 29,898 of 40,283 ZIP codes nationally. Within IL, it ranks 1,451 of 1,548.
Learn more
zone vs. frost date explains why Zone 5b and Sterling's frost date answer different questions, and the frost range explains how to read the range around Sterling's dates instead of trusting one.