Onarga, IL 60955 Frost Dates
Frost dates for Onarga, IL, ZIP 60955
The last spring frost here typically falls around 04/25, about 240 days from today. The first fall frost typically arrives around 10/20, about 175 frost-free days later.
Onarga 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 Onarga has about 8 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.
The actual range around Onarga's last frost
04/25 is the middle of 30 years of NOAA records, not a promise. Plant by 04/11 and you're betting against frost in roughly 9 years out of 10. 05/10 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Onarga compares
Onarga's growing season runs about 175 days, ranking 27,056 of 40,283 US ZIP codes measured here, longest to shortest. Within IL, it ranks 1,201 of 1,548.
Learn more
zone vs. frost date explains why Zone 5b and Onarga's frost date answer different questions, and the frost range explains how to read the range around Onarga's dates instead of trusting one.