Humphreys, MO 64646 Frost Dates
64646, near Humphreys, MO: the frost window
Around 04/16 is the usual last spring frost, about 231 days away. Fall's first freeze usually shows up around 10/20, roughly 184 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Humphreys 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
Humphreys'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 04/16 isn't a guarantee
04/16 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/03 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/29 and only about 1 year in 10 sees frost after that.
Humphreys against the rest of the dataset
Humphreys's growing season runs about 184 days, ranking 23,689 of 40,283 US ZIP codes measured here, longest to shortest. Within MO, it ranks 944 of 1,129.
Learn more
Two guides worth reading on 64646: local microclimates, on what one yard in Humphreys can differ from the 64646 normal, and zone vs. frost date, on why Zone 6a and Humphreys's frost date answer different questions.