Washington, DC 20057 Frost Dates
Washington, DC: when does the frost end?
Around 03/29 is the usual last spring frost, about 213 days away. Fall's first freeze usually shows up around 11/08, roughly 224 days after the last spring frost.
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 Washington, not a forecast for this year.
Stretching the season past the first frost
With roughly 10 weeks until Washington's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Washington's last frost
03/29 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/15 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/11 and only about 1 year in 10 sees frost after that.
Washington against the rest of the dataset
Washington's growing season runs about 224 days, ranking 11,548 of 40,283 US ZIP codes measured here, longest to shortest. Within DC, it ranks 76 of 246.
Learn more
Before leaning on 20057's figures: the frost range explains how to read the range around Washington's dates instead of trusting one, while local microclimates explains what one yard in Washington can differ from the 20057 normal.