Flanagan, IL 61743 Frost Dates
Frost dates for Flanagan, IL, ZIP 61743
The last spring frost here typically falls around 04/16, about 231 days from today. The first fall frost typically arrives around 10/24, about 191 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 Flanagan, not a forecast for this year.
What to do before the first frost
Zone 5b around Flanagan 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.
How much risk comes with planting early here
04/16 is the middle of 30 years of NOAA records, not a promise. Plant by 04/03 and you're betting against frost in roughly 9 years out of 10. 05/02 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Flanagan compares
About 191 days separate Flanagan's last and first frost, putting it 20,834 of 40,283 ZIP codes nationally. Within IL, it ranks 454 of 1,548.
Learn more
local microclimates explains what one yard in Flanagan can differ from the 61743 normal, and zone vs. frost date explains why Zone 5b and Flanagan's frost date answer different questions.