Riverdale, IL 60827 Frost Dates
Frost dates for Riverdale, IL, ZIP 60827
The last spring frost here typically falls around 04/10, about 225 days from today. The first fall frost typically arrives around 11/01, about 203 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 Riverdale, not a forecast for this year.
What to do before the first frost
Zone 6a around Riverdale 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 04/10 isn't a guarantee
04/10 is the middle of 30 years of NOAA records, not a promise. Plant by 03/30 and you're betting against frost in roughly 9 years out of 10. 04/26 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Riverdale compares
Riverdale's growing season runs about 203 days, ranking 16,872 of 40,283 US ZIP codes measured here, longest to shortest. Within IL, it ranks 159 of 1,548.
Learn more
the frost range explains how to read the range around Riverdale's dates instead of trusting one, and local microclimates explains what one yard in Riverdale can differ from the 60827 normal.