Harwood Heights, IL 60630 Frost Dates
Harwood Heights, IL: when does the frost end?
Typically, the last spring freeze lands around 04/16, roughly 231 days out. Fall's first freeze usually shows up around 10/28, roughly 193 days after the last spring frost.
Harwood Heights 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.
Stretching the season past the first frost
With roughly 9 weeks until Harwood Heights's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 04/16 isn't a guarantee
04/16 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/03 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/01 and only about 1 year in 10 sees frost after that.
Harwood Heights against the rest of the dataset
About 193 days separate Harwood Heights's last and first frost, putting it 19,785 of 40,283 ZIP codes nationally. Within IL, it ranks 391 of 1,548.
Learn more
Before leaning on 60630's figures: zone vs. frost date explains why Zone 6a and Harwood Heights's frost date answer different questions, while the frost range explains how to read the range around Harwood Heights's dates instead of trusting one.