Washington, DC 20388 Frost Dates
Frost dates for Washington, DC, ZIP 20388
Typically, the last spring freeze lands around 03/24, roughly 208 days out. The first fall frost typically arrives around 11/18, about 241 frost-free days later.
Washington sits in USDA Zone 8a (10 to 15°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 8a around Washington 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 03/07 and you're betting against frost in roughly 9 years out of 10. 04/06 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Washington compares
Washington's growing season runs about 241 days, ranking 8,437 of 40,283 US ZIP codes measured here, longest to shortest. Within DC, it ranks 18 of 246.
Learn more
local microclimates explains what one yard in Washington can differ from the 20388 normal, and zone vs. frost date explains why Zone 8a and Washington's frost date answer different questions.