Coal Valley, IL 61240 Frost Dates
Coal Valley, IL: when does the frost end?
Typically, the last spring freeze lands around 04/24, roughly 239 days out. Fall's first freeze usually shows up around 10/18, roughly 176 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 Coal Valley, not a forecast for this year.
Stretching the season past the first frost
With roughly 7 weeks until Coal Valley's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Coal Valley's last frost
04/24 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/09 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/09 and only about 1 year in 10 sees frost after that.
Coal Valley against the rest of the dataset
Coal Valley's growing season runs about 176 days, ranking 26,445 of 40,283 US ZIP codes measured here, longest to shortest. Within IL, it ranks 1,173 of 1,548.
Learn more
Before leaning on 61240's figures: zone vs. frost date explains why Zone 5b and Coal Valley's frost date answer different questions, while the frost range explains how to read the range around Coal Valley's dates instead of trusting one.