Baltimore, MD 21227 Frost Dates
Frost dates for Baltimore, MD, ZIP 21227
The last spring frost here typically falls around 03/24, about 208 days from today. The first fall frost typically arrives around 11/21, about 244 frost-free days later.
Zone 7b (5 to 10°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
Zone 7b around Baltimore has about 12 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
How much risk comes with planting early here
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 8,164 of 40,283 ZIP codes in this dataset. Within MD, it ranks 33 of 583.
Learn more
the frost range explains how to read the range around Baltimore's dates instead of trusting one, and local microclimates explains what one yard in Baltimore can differ from the 21227 normal.