Washington, DC 20392 Frost Dates
20392, 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 7b (5 to 10°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.
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 11,629 of 40,283 ZIP codes in this dataset. Within DC, it ranks 157 of 246.
Learn more
Two guides worth reading on 20392: zone vs. frost date, on why Zone 7b and Washington's frost date answer different questions, and the frost range, on how to read the range around Washington's dates instead of trusting one.