Washington, DC 20208 Frost Dates
20208, near Washington, DC: the frost window
Typically, the last spring freeze lands around 03/29, roughly 213 days out. Fall's first freeze usually shows up around 11/08, roughly 224 days after the last spring frost.
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.
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.
How much risk comes with planting early here
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 11,574 of 40,283 US ZIP codes measured here, longest to shortest. Within DC, it ranks 102 of 246.
Learn more
Two guides worth reading on 20208: local microclimates, on what one yard in Washington can differ from the 20208 normal, and zone vs. frost date, on why Zone 8a and Washington's frost date answer different questions.