Washington, DC 20244 Frost Dates
20244, near Washington, DC: the frost window
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.
The USDA Plant Hardiness Zone Map puts Washington in Zone 8a (10 to 15°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
Washington's growing season runs out in roughly 10 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 03/29 isn't a guarantee
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
At roughly 224 frost-free days, Washington places 11,599 of 40,283 ZIP codes in this dataset. Within DC, it ranks 127 of 246.
Learn more
Two guides worth reading on 20244: the frost range, on how to read the range around Washington's dates instead of trusting one, and local microclimates, on what one yard in Washington can differ from the 20244 normal.