Baltimore, MD 21221 Frost Dates
When can you plant in Baltimore, MD?
Typically, the last spring freeze lands around 03/24, roughly 208 days out. The first fall frost typically arrives around 11/21, about 244 frost-free days later.
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.
What to do before the first frost
About 12 weeks of growing season left in Baltimore before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 03/24 isn't a guarantee
03/24 is the middle of 30 years of NOAA records, not a promise. Plant by 03/08 and you're betting against frost in roughly 9 years out of 10. 04/04 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Baltimore compares
At roughly 244 frost-free days, Baltimore places 8,158 of 40,283 ZIP codes in this dataset. Within MD, it ranks 27 of 583.
Learn more
local microclimates covers what one yard in Baltimore can differ from the 21221 normal. zone vs. frost date covers why Zone 8a and Baltimore's frost date answer different questions.