Washington, DC 20535 Frost Dates
When can you plant in Washington, DC?
Around 03/24 is the usual last spring frost, about 208 days away. The first fall frost typically arrives around 11/18, about 241 frost-free days later.
Zone 8a (10 to 15°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 Washington, not a forecast for this year.
What to do before the first frost
About 12 weeks of growing season left in Washington before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 03/24 isn't a guarantee
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
About 241 days separate Washington's last and first frost, putting it 8,457 of 40,283 ZIP codes nationally. Within DC, it ranks 38 of 246.
Learn more
local microclimates covers what one yard in Washington can differ from the 20535 normal. zone vs. frost date covers why Zone 8a and Washington's frost date answer different questions.