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When to plant in Washington, DC

USDA Zone 8a

Washington, District of Columbia frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.

Zone 8a means many perennials and even some tender shrubs overwinter in Washington, while your frost dates still decide when annuals go out.

Station · NATL ARBORETUM DC · 4.1 km
Last spring frost
March 29
50% chance · 32°F
First fall frost
November 8
50% chance · 32°F
Growing season
224 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for WashingtonA year-band showing 32°F frost risk from January to December for Washington: last spring frost around March 29, first fall frost around November 8, about 224 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

The average first fall frost in Washington is now 5 days later than in the 1981–2010 normals. See how frost dates are shifting nationwide →

Frost probability

NATL ARBORETUM DC · 1991–2020

The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Washington’s own odds, recorded at NATL ARBORETUM DC.

Frost-probability curves for WashingtonProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around March 29 and the first fall frost around November 8, giving about 224 frost-free days.
Last spring frostFirst fall frostbold = 32°F · thin = 28°F / 36°F · dot = 50% date · band = 10–90% window
ThresholdSPRING 10%SPRING 50%SPRING 90%FALL 10%FALL 50%FALL 90%
36°FApr 28Apr 10Mar 29Oct 14Oct 29Nov 10
32°FApr 11Mar 29Mar 15Oct 26Nov 8Nov 23
28°FMar 31Mar 17Mar 2Nov 6Nov 20Dec 7

Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.

What to plant now

TODAY · JULY 19
Fall sowopen now
Brussels Sprouts
July 19August 2
Fall sowin 14 days
Rutabaga
August 2August 16
Fall sowin 28 days
Broccoli
August 16August 30
Fall sowin 28 days
Cabbage
August 16August 30
Fall sowin 28 days
Carrot
August 16August 30
Fall sowin 28 days
Cauliflower
August 16August 30
Fall sowin 28 days
Napa Cabbage
August 16September 13

Add these crops to your calendar (.ics) ↓

Full-year planting calendar

Start indoorsTransplantDirect sowFall sow

Each bar is the exact window to take a planting action in Washington, drawn to the day from the local frost dates. The dashed line is today.

Nearby weather stations

3 within 9 km · complete 32°F normals

When stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.

NATL ARBORETUM DC
Primary
4 km · 15 m elevation
SPRING
Mar 29
FALL
Nov 8
WASHINGTON REAGAN AP
6 km · 3 m elevation
SPRING
Mar 24
FALL
Nov 18
DALECARLIA RSVR
9 km · 46 m elevation
SPRING
Apr 9
FALL
Oct 31

Washington planting FAQ

When is the last spring frost in Washington, DC?

Plan for the last spring frost in Washington around March 29 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.

When is the first fall frost in Washington, DC?

Expect Washington's first fall frost near November 8 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.

What hardiness zone is Washington in?

Washington is in USDA hardiness zone 8a. In zone 8a, winters are mild — many tender perennials overwinter here.

How long is the growing season in Washington?

There are roughly 224 frost-free days in Washington (a long growing season), running from the average last frost around March 29 to the first fall frost near November 8.

When should I plant tomatoes in Washington?

In Washington, start tomato seeds indoors around February 1–February 15, then transplant seedlings outdoors around April 5 once the danger of frost has passed.

Planting reminders

Never miss a window in Washington

An email when it’s time to start seeds, transplant, and sow — timed to Washington’s frost dates. Double opt-in, one-click unsubscribe, no spam.

Nearby cities

8 within reach

Frost dates recorded at NATL ARBORETUM DC, 4 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.

Cite this page
BlissGarden. "When to Plant in Washington, DC — Frost Dates & Zone 8a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00186350. Retrieved from https://blissgarden.com/district-of-columbia/washington.