Wilmette, IL 60091 Frost Dates
When can you plant in Wilmette, IL?
Around 04/26 is the usual last spring frost, about 241 days away. The first fall frost typically arrives around 10/21, about 176 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 Wilmette, not a forecast for this year.
What to do before the first frost
About 8 weeks of growing season left in Wilmette before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
How much risk comes with planting early here
04/26 is the middle of 30 years of NOAA records, not a promise. Plant by 04/11 and you're betting against frost in roughly 9 years out of 10. 05/11 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Wilmette compares
Wilmette's growing season runs about 176 days, ranking 26,381 of 40,283 US ZIP codes measured here, longest to shortest. Within IL, it ranks 1,158 of 1,548.
Learn more
zone vs. frost date covers why Zone 6a and Wilmette's frost date answer different questions. the frost range covers how to read the range around Wilmette's dates instead of trusting one.