blissgarden.

When to plant in Fort Lewis, WA

USDA Zone 8b

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

With about 255 frost-free days, Fort Lewis supports back-to-back plantings; stagger sowings every few weeks to keep beds productive spring through fall. Heads up: the nearest complete-normals station is about 19 km from Fort Lewis, so your yard's frost dates can differ — a low spot or a paved city center can shift them by a week. Zone 8b means many perennials and even some tender shrubs overwinter in Fort Lewis, while your frost dates still decide when annuals go out.

Station · TACOMA NARROWS AP · 19.1 km
Last spring frost
March 11
50% chance · 32°F
First fall frost
November 21
50% chance · 32°F
Growing season
255 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for Fort LewisA year-band showing 32°F frost risk from January to December for Fort Lewis: last spring frost around March 11, first fall frost around November 21, about 255 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

Frost probability

TACOMA NARROWS AP · 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 Fort Lewis’s own odds, recorded at TACOMA NARROWS AP.

Frost-probability curves for Fort LewisProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around March 11 and the first fall frost around November 21, giving about 255 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 2Apr 11Mar 26Oct 21Nov 4Nov 19
32°FApr 2Mar 11Feb 15Nov 3Nov 21Dec 10
28°FMar 8Feb 13Jan 1Nov 18Dec 11Jan 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 sowin 13 days
Brussels Sprouts
August 1August 15
Fall sowin 27 days
Rutabaga
August 15August 29

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 Fort Lewis, drawn to the day from the local frost dates. The dashed line is today.

Nearby weather stations

3 within 24 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.

TACOMA NARROWS AP
Primary
19 km · 89 m elevation
SPRING
Mar 11
FALL
Nov 21
TACOMA #1
21 km · 8 m elevation
SPRING
Mar 8
FALL
Nov 14
MCMILLIN RSVR
24 km · 177 m elevation
SPRING
Apr 11
FALL
Oct 30

Fort Lewis planting FAQ

When is the last spring frost in Fort Lewis, WA?

On average, the last spring frost in Fort Lewis is around March 11 (50% probability at 32°F, from 1991–2020 NOAA normals). Wait until after this date to set out tender plants like tomatoes and peppers.

When is the first fall frost in Fort Lewis, WA?

Expect Fort Lewis's first fall frost near November 21 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.

What hardiness zone is Fort Lewis in?

Fort Lewis is in USDA hardiness zone 8b. In zone 8b, winters are mild — many tender perennials overwinter here.

How long is the growing season in Fort Lewis?

There are roughly 255 frost-free days in Fort Lewis (a long growing season), running from the average last frost around March 11 to the first fall frost near November 21.

When should I plant tomatoes in Fort Lewis?

In Fort Lewis, start tomato seeds indoors around January 14–January 28, then transplant seedlings outdoors around March 18 once the danger of frost has passed.

Planting reminders

Never miss a window in Fort Lewis

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

Nearby cities

8 within reach

Frost dates recorded at TACOMA NARROWS AP, 19 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 Fort Lewis, WA — Frost Dates & Zone 8b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00094274. Retrieved from https://blissgarden.com/washington/fort-lewis.
When to Plant in Fort Lewis, WA — Frost Dates & Zone 8b — BlissGarden