FrostDateCheck

Washington, DC 20502 Frost Dates

Frost dates for Washington, DC, ZIP 20502

Zone 8a

The last spring frost here typically falls around 03/24, about 208 days from today. The first fall frost typically arrives around 11/18, about 241 frost-free days later.

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.

What to do before the first frost

Zone 8a around Washington has about 12 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.

How much risk comes with planting early here

03/24 is the middle of 30 years of NOAA records, not a promise. Plant by 03/07 and you're betting against frost in roughly 9 years out of 10. 04/06 is the safer bet, historically only a 1-in-10 chance of frost that late.

How Washington compares

At roughly 241 frost-free days, Washington places 8,450 of 40,283 ZIP codes in this dataset. Within DC, it ranks 31 of 246.

Learn more

zone vs. frost date explains why Zone 8a 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.