Winthrop Harbor, IL 60096 Frost Dates
When can you plant in Winthrop Harbor, IL?
Typically, the last spring freeze lands around 04/30, roughly 245 days out. The first fall frost typically arrives around 10/21, about 173 frost-free days later.
Winthrop Harbor 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 8 weeks of growing season left in Winthrop Harbor before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Winthrop Harbor's last frost
04/30 is the middle of 30 years of NOAA records, not a promise. Plant by 04/14 and you're betting against frost in roughly 9 years out of 10. 05/16 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Winthrop Harbor compares
At roughly 173 frost-free days, Winthrop Harbor places 27,838 of 40,283 ZIP codes in this dataset. Within IL, it ranks 1,317 of 1,548.
Learn more
local microclimates covers what one yard in Winthrop Harbor can differ from the 60096 normal. zone vs. frost date covers why Zone 6a and Winthrop Harbor's frost date answer different questions.