Winthrop Harbor, IL 53194 Frost Dates
53194, near Winthrop Harbor, IL: the frost window
The last spring frost here typically falls around 04/19, about 234 days from today. Fall's first freeze usually shows up around 10/26, roughly 189 days after the last spring frost.
Winthrop Harbor sits in USDA Zone 5b (-15 to -10°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.
Stretching the season past the first frost
Winthrop Harbor's growing season runs out in roughly 8 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around Winthrop Harbor's last frost
04/19 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/06 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/03 and only about 1 year in 10 sees frost after that.
Winthrop Harbor against the rest of the dataset
About 189 days separate Winthrop Harbor's last and first frost, putting it 21,521 of 40,283 ZIP codes nationally. Within IL, it ranks 583 of 1,548.
Learn more
Two guides worth reading on 53194: zone vs. frost date, on why Zone 5b and Winthrop Harbor's frost date answer different questions, and the frost range, on how to read the range around Winthrop Harbor's dates instead of trusting one.