Dearborn, MO 64439 Frost Dates
64439, near Dearborn, MO: the frost window
Around 04/18 is the usual last spring frost, about 233 days away. Fall's first freeze usually shows up around 10/20, roughly 183 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Dearborn in Zone 6a (-10 to -5°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
Dearborn'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.
The actual range around Dearborn's last frost
04/18 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/04 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/03 and only about 1 year in 10 sees frost after that.
Dearborn against the rest of the dataset
Dearborn's growing season runs about 183 days, ranking 23,985 of 40,283 US ZIP codes measured here, longest to shortest. Within MO, it ranks 966 of 1,129.
Learn more
Two guides worth reading on 64439: the frost range, on how to read the range around Dearborn's dates instead of trusting one, and local microclimates, on what one yard in Dearborn can differ from the 64439 normal.