Leonardtown, MD 20629 Frost Dates
20629, near Leonardtown, MD: the frost window
Around 03/22 is the usual last spring frost, about 206 days away. Fall's first freeze usually shows up around 11/26, roughly 248 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Leonardtown in Zone 8a (10 to 15°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
Leonardtown's growing season runs out in roughly 13 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 03/22 isn't a guarantee
03/22 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/06 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/05 and only about 1 year in 10 sees frost after that.
Leonardtown against the rest of the dataset
About 248 days separate Leonardtown's last and first frost, putting it 7,700 of 40,283 ZIP codes nationally. Within MD, it ranks 7 of 583.
Learn more
Two guides worth reading on 20629: local microclimates, on what one yard in Leonardtown can differ from the 20629 normal, and zone vs. frost date, on why Zone 8a and Leonardtown's frost date answer different questions.