Nason, IL 62866 Frost Dates
Frost dates for Nason, IL, ZIP 62866
The last spring frost here typically falls around 04/04, about 219 days from today. The first fall frost typically arrives around 10/27, about 204 frost-free days later.
Nason sits in USDA Zone 6b (-5 to 0°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 6b around Nason has about 9 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 04/04 isn't a guarantee
04/04 is the middle of 30 years of NOAA records, not a promise. Plant by 03/21 and you're betting against frost in roughly 9 years out of 10. 04/19 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Nason compares
About 204 days separate Nason's last and first frost, putting it 16,776 of 40,283 ZIP codes nationally. Within IL, it ranks 145 of 1,548.
Learn more
the frost range explains how to read the range around Nason's dates instead of trusting one, and local microclimates explains what one yard in Nason can differ from the 62866 normal.