Baltimore, MD 21275 Frost Dates
Baltimore, MD: when does the frost end?
Typically, the last spring freeze lands around 03/24, roughly 208 days out. Fall's first freeze usually shows up around 11/21, roughly 244 days after the last spring frost.
Zone 8a (10 to 15°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Baltimore, not a forecast for this year.
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.
How much risk comes with planting early here
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
Baltimore's growing season runs about 244 days, ranking 8,177 of 40,283 US ZIP codes measured here, longest to shortest. Within MD, it ranks 46 of 583.
Learn more
Before leaning on 21275's figures: zone vs. frost date explains why Zone 8a and Baltimore's frost date answer different questions, while the frost range explains how to read the range around Baltimore's dates instead of trusting one.