Leonardtown, MD 20618 Frost Dates
20618, near Leonardtown, MD: the frost window
Around 04/17 is the usual last spring frost, about 232 days away. Fall's first freeze usually shows up around 10/27, roughly 195 days after the last spring frost.
Leonardtown sits in USDA Zone 8a (10 to 15°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
Leonardtown's growing season runs out in roughly 9 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
How much risk comes with planting early here
04/17 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/31 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/02 and only about 1 year in 10 sees frost after that.
Leonardtown against the rest of the dataset
Leonardtown's growing season runs about 195 days, ranking 19,251 of 40,283 US ZIP codes measured here, longest to shortest. Within MD, it ranks 508 of 583.
Learn more
Two guides worth reading on 20618: the frost range, on how to read the range around Leonardtown's dates instead of trusting one, and local microclimates, on what one yard in Leonardtown can differ from the 20618 normal.