Shannon, IL 61078 Frost Dates
Frost dates for Shannon, IL, ZIP 61078
The last spring frost here typically falls around 04/26, about 241 days from today. The first fall frost typically arrives around 10/13, about 169 frost-free days later.
The USDA Plant Hardiness Zone Map puts Shannon in Zone 5a (-20 to -15°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 5a around Shannon 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.
The actual range around Shannon's last frost
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. 05/11 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Shannon compares
Shannon's growing season runs about 169 days, ranking 29,527 of 40,283 US ZIP codes measured here, longest to shortest. Within IL, it ranks 1,432 of 1,548.
Learn more
local microclimates explains what one yard in Shannon can differ from the 61078 normal, and zone vs. frost date explains why Zone 5a and Shannon's frost date answer different questions.