Oregon, IL 61015 Frost Dates
Frost dates for Oregon, IL, ZIP 61015
Typically, the last spring freeze lands around 04/26, roughly 241 days out. The first fall frost typically arrives around 10/13, about 168 frost-free days later.
Zone 5b (-15 to -10°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Oregon, not a forecast for this year.
What to do before the first frost
Zone 5b around Oregon 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 04/11 and you're betting against frost in roughly 9 years out of 10. 05/12 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Oregon compares
At roughly 168 frost-free days, Oregon places 29,708 of 40,283 ZIP codes in this dataset. Within IL, it ranks 1,441 of 1,548.
Learn more
local microclimates explains what one yard in Oregon can differ from the 61015 normal, and zone vs. frost date explains why Zone 5b and Oregon's frost date answer different questions.