Baltimore, MD 21231 Frost Dates
Baltimore, MD: when does the frost end?
Around 03/24 is the usual last spring frost, about 208 days away. Fall's first freeze usually shows up around 11/21, roughly 244 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Baltimore 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
With roughly 12 weeks until Baltimore's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Baltimore's last frost
03/24 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/08 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/04 and only about 1 year in 10 sees frost after that.
Baltimore against the rest of the dataset
At roughly 244 frost-free days, Baltimore places 8,167 of 40,283 ZIP codes in this dataset. Within MD, it ranks 36 of 583.
Learn more
Before leaning on 21231's figures: the frost range explains how to read the range around Baltimore's dates instead of trusting one, while local microclimates explains what one yard in Baltimore can differ from the 21231 normal.