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When to plant in Sedro-Woolley, WA

USDA Zone 8b

Here are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Sedro-Woolley, Washington — all computed from Sedro-Woolley's nearest NOAA weather station.

In zone 8b, Sedro-Woolley supports a wide range of perennials year-round; the frost dates above are what set your annual vegetable timing.

Station · SEDRO-WOOLLEY · 1.8 km
Last spring frost
March 27
50% chance · 32°F
First fall frost
November 6
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 Sedro-WoolleyA year-band showing 32°F frost risk from January to December for Sedro-Woolley: last spring frost around March 27, first fall frost around November 6, about 224 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

Frost probability

SEDRO-WOOLLEY · 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 Sedro-Woolley’s own odds, recorded at SEDRO-WOOLLEY.

Frost-probability curves for Sedro-WoolleyProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around March 27 and the first fall frost around November 6, 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°FMay 11Apr 22Apr 1Oct 1Oct 17Nov 8
32°FApr 17Mar 27Mar 8Oct 15Nov 6Nov 28
28°FMar 22Mar 1Feb 2Nov 1Nov 24Dec 19

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 17July 31
Fall sowin 12 days
Rutabaga
July 31August 14
Fall sowin 26 days
Broccoli
August 14August 28
Fall sowin 26 days
Cabbage
August 14August 28
Fall sowin 26 days
Carrot
August 14August 28
Fall sowin 26 days
Cauliflower
August 14August 28
Fall sowin 26 days
Napa Cabbage
August 14September 11

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 Sedro-Woolley, drawn to the day from the local frost dates. The dashed line is today.

Nearby weather stations

3 within 28 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.

SEDRO-WOOLLEY
Primary
2 km · 18 m elevation
SPRING
Mar 27
FALL
Nov 6
MT VERNON 3 WNW
14 km · 4 m elevation
SPRING
Mar 24
FALL
Nov 3
ANACORTES
28 km · 6 m elevation
SPRING
Mar 8
FALL
Nov 20

Sedro-Woolley planting FAQ

When is the last spring frost in Sedro-Woolley, WA?

Sedro-Woolley's average last spring frost falls near March 27 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.

When is the first fall frost in Sedro-Woolley, WA?

Expect Sedro-Woolley's first fall frost near November 6 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.

What hardiness zone is Sedro-Woolley in?

Sedro-Woolley is in USDA hardiness zone 8b. In zone 8b, winters are mild — many tender perennials overwinter here.

How long is the growing season in Sedro-Woolley?

Sedro-Woolley has about 224 frost-free days — a long growing season — between the average last spring frost (March 27) and first fall frost (November 6).

When should I plant tomatoes in Sedro-Woolley?

For Sedro-Woolley, sow tomatoes indoors about January 30–February 13 and move the seedlings out around April 3, after the last spring frost.

Planting reminders

Never miss a window in Sedro-Woolley

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

Nearby cities

8 within reach

Frost dates recorded at SEDRO-WOOLLEY, 2 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 Sedro-Woolley, WA — Frost Dates & Zone 8b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00457507. Retrieved from https://blissgarden.com/washington/sedro-woolley.
When to Plant in Sedro-Woolley, WA — Frost Dates & Zone 8b — BlissGarden