Chatham, IL 62629 Frost Dates
Frost dates for Chatham, IL, ZIP 62629
Typically, the last spring freeze lands around 04/14, roughly 229 days out. The first fall frost typically arrives around 10/20, about 187 frost-free days later.
Zone 6a (-10 to -5°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 Chatham, not a forecast for this year.
What to do before the first frost
Zone 6a around Chatham 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 Chatham's last frost
04/14 is the middle of 30 years of NOAA records, not a promise. Plant by 04/01 and you're betting against frost in roughly 9 years out of 10. 04/29 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Chatham compares
Chatham's growing season runs about 187 days, ranking 22,312 of 40,283 US ZIP codes measured here, longest to shortest. Within IL, it ranks 716 of 1,548.
Learn more
the frost range explains how to read the range around Chatham's dates instead of trusting one, and local microclimates explains what one yard in Chatham can differ from the 62629 normal.