Washington, DC 20058 Frost Dates
Frost dates for Washington, DC, ZIP 20058
Typically, the last spring freeze lands around 03/29, roughly 213 days out. The first fall frost typically arrives around 11/08, about 224 frost-free days later.
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.
What to do before the first frost
Zone 7b around Washington has about 10 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
Why 03/29 isn't a guarantee
03/29 is the middle of 30 years of NOAA records, not a promise. Plant by 03/15 and you're betting against frost in roughly 9 years out of 10. 04/11 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Washington compares
Washington's growing season runs about 224 days, ranking 11,549 of 40,283 US ZIP codes measured here, longest to shortest. Within DC, it ranks 77 of 246.
Learn more
zone vs. frost date explains why Zone 7b and Washington's frost date answer different questions, and the frost range explains how to read the range around Washington's dates instead of trusting one.