Ste. Marie, IL 62475 Frost Dates
When can you plant in Ste. Marie, IL?
The last spring frost here typically falls around 04/13, about 228 days from today. The first fall frost typically arrives around 10/22, about 190 frost-free days later.
The USDA Plant Hardiness Zone Map puts Ste. Marie in Zone 6b (-5 to 0°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
About 8 weeks of growing season left in Ste. Marie before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 04/13 isn't a guarantee
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
Ste. Marie's growing season runs about 190 days, ranking 21,307 of 40,283 US ZIP codes measured here, longest to shortest. Within IL, it ranks 541 of 1,548.
Learn more
local microclimates covers what one yard in Ste. Marie can differ from the 62475 normal. zone vs. frost date covers why Zone 6b and Ste. Marie's frost date answer different questions.