Kitzmiller, MD 21538 Frost Dates
21538, near Kitzmiller, MD: the frost window
Typically, the last spring freeze lands around 04/29, roughly 244 days out. Fall's first freeze usually shows up around 10/20, roughly 174 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Kitzmiller 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
Kitzmiller'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 04/29 isn't a guarantee
04/29 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/11 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/15 and only about 1 year in 10 sees frost after that.
Kitzmiller against the rest of the dataset
At roughly 174 frost-free days, Kitzmiller places 27,620 of 40,283 ZIP codes in this dataset. Within MD, it ranks 568 of 583.
Learn more
Two guides worth reading on 21538: local microclimates, on what one yard in Kitzmiller can differ from the 21538 normal, and zone vs. frost date, on why Zone 6a and Kitzmiller's frost date answer different questions.