FrostDateCheck

Willowbrook, IL 60514 Frost Dates

When can you plant in Willowbrook, IL?

Zone 6a

Typically, the last spring freeze lands around 04/27, roughly 242 days out. The first fall frost typically arrives around 10/17, about 173 frost-free days later.

Willowbrook sits in USDA Zone 6a (-10 to -5°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

About 7 weeks of growing season left in Willowbrook 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

04/27 is the middle of 30 years of NOAA records, not a promise. Plant by 04/12 and you're betting against frost in roughly 9 years out of 10. 05/14 is the safer bet, historically only a 1-in-10 chance of frost that late.

How Willowbrook compares

Willowbrook's growing season runs about 173 days, ranking 27,818 of 40,283 US ZIP codes measured here, longest to shortest. Within IL, it ranks 1,315 of 1,548.

Learn more

local microclimates covers what one yard in Willowbrook can differ from the 60514 normal. zone vs. frost date covers why Zone 6a and Willowbrook's frost date answer different questions.