Ste. Marie, IL 62459 Frost Dates
Frost dates for Ste. Marie, IL, ZIP 62459
Around 04/13 is the usual last spring frost, about 228 days away. The first fall frost typically arrives around 10/22, about 190 frost-free days later.
Ste. Marie 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 Ste. Marie 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
04/13 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 Ste. Marie compares
At roughly 190 frost-free days, Ste. Marie places 21,306 of 40,283 ZIP codes in this dataset. Within IL, it ranks 540 of 1,548.
Learn more
the frost range explains how to read the range around Ste. Marie's dates instead of trusting one, and local microclimates explains what one yard in Ste. Marie can differ from the 62459 normal.