Baltimore, MD 21090 Frost Dates
Frost dates for Baltimore, MD, ZIP 21090
Typically, the last spring freeze lands around 04/10, roughly 225 days out. The first fall frost typically arrives around 10/31, about 204 frost-free days later.
Baltimore sits in USDA Zone 7b (5 to 10°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
What to do before the first frost
Zone 7b around Baltimore has about 9 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.
The actual range around Baltimore's last frost
04/10 is the middle of 30 years of NOAA records, not a promise. Plant by 03/27 and you're betting against frost in roughly 9 years out of 10. 04/25 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Baltimore compares
About 204 days separate Baltimore's last and first frost, putting it 16,437 of 40,283 ZIP codes nationally. Within MD, it ranks 361 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 21090 normal.