Windsor, IL 61465 Frost Dates
Windsor, IL: when does the frost end?
Typically, the last spring freeze lands around 04/22, roughly 237 days out. Fall's first freeze usually shows up around 10/19, roughly 181 days after the last spring frost.
Zone 5b (-15 to -10°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 Windsor, not a forecast for this year.
Stretching the season past the first frost
With roughly 7 weeks until Windsor's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 04/22 isn't a guarantee
04/22 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/07 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/06 and only about 1 year in 10 sees frost after that.
Windsor against the rest of the dataset
At roughly 181 frost-free days, Windsor places 24,670 of 40,283 ZIP codes in this dataset. Within IL, it ranks 930 of 1,548.
Learn more
Before leaning on 61465's figures: zone vs. frost date explains why Zone 5b and Windsor's frost date answer different questions, while the frost range explains how to read the range around Windsor's dates instead of trusting one.