Charlestown, MD 21916 Frost Dates
Frost dates for Charlestown, MD, ZIP 21916
The last spring frost here typically falls around 04/10, about 225 days from today. The first fall frost typically arrives around 10/30, about 201 frost-free days later.
The USDA Plant Hardiness Zone Map puts Charlestown in Zone 7a (0 to 5°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
Zone 7a around Charlestown 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.
Why 04/10 isn't a guarantee
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. 04/30 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Charlestown compares
About 201 days separate Charlestown's last and first frost, putting it 17,546 of 40,283 ZIP codes nationally. Within MD, it ranks 459 of 583.
Learn more
the frost range explains how to read the range around Charlestown's dates instead of trusting one, and local microclimates explains what one yard in Charlestown can differ from the 21916 normal.