Mascoutah, IL 62258 Frost Dates
62258, near Mascoutah, IL: the frost window
Around 04/12 is the usual last spring frost, about 227 days away. Fall's first freeze usually shows up around 10/20, roughly 189 days after the last spring frost.
Zone 6b (-5 to 0°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 Mascoutah, not a forecast for this year.
Stretching the season past the first frost
Mascoutah'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.
Why 04/12 isn't a guarantee
04/12 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/28 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/28 and only about 1 year in 10 sees frost after that.
Mascoutah against the rest of the dataset
Mascoutah's growing season runs about 189 days, ranking 21,479 of 40,283 US ZIP codes measured here, longest to shortest. Within IL, it ranks 578 of 1,548.
Learn more
Two guides worth reading on 62258: the frost range, on how to read the range around Mascoutah's dates instead of trusting one, and local microclimates, on what one yard in Mascoutah can differ from the 62258 normal.