Sibley, IL 61773 Frost Dates
Sibley, IL: when does the frost end?
Typically, the last spring freeze lands around 04/21, roughly 236 days out. Fall's first freeze usually shows up around 10/17, roughly 178 days after the last spring frost.
Zone 6a (-10 to -5°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 Sibley, not a forecast for this year.
Stretching the season past the first frost
With roughly 7 weeks until Sibley's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
04/21 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/10 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/05 and only about 1 year in 10 sees frost after that.
Sibley against the rest of the dataset
About 178 days separate Sibley's last and first frost, putting it 25,908 of 40,283 ZIP codes nationally. Within IL, it ranks 1,106 of 1,548.
Learn more
Before leaning on 61773's figures: local microclimates explains what one yard in Sibley can differ from the 61773 normal, while zone vs. frost date explains why Zone 6a and Sibley's frost date answer different questions.