Baltimore, MD 21285 Frost Dates
Frost dates for Baltimore, MD, ZIP 21285
Around 04/02 is the usual last spring frost, about 217 days away. The first fall frost typically arrives around 11/07, about 220 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 10 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
04/02 is the middle of 30 years of NOAA records, not a promise. Plant by 03/20 and you're betting against frost in roughly 9 years out of 10. 04/13 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Baltimore compares
Baltimore's growing season runs about 220 days, ranking 12,655 of 40,283 US ZIP codes measured here, longest to shortest. Within MD, it ranks 162 of 583.
Learn more
zone vs. frost date explains why Zone 7b and Baltimore's frost date answer different questions, and the frost range explains how to read the range around Baltimore's dates instead of trusting one.