Washington, DC 20220 Frost Dates
Washington, DC: when does the frost end?
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.
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
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
At roughly 224 frost-free days, Washington places 11,585 of 40,283 ZIP codes in this dataset. Within DC, it ranks 113 of 246.
Learn more
Before leaning on 20220's figures: local microclimates explains what one yard in Washington can differ from the 20220 normal, while zone vs. frost date explains why Zone 8a and Washington's frost date answer different questions.