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When to plant in Kirkland, WA

USDA Zone 9a

Everything below — frost dates, hardiness zone, and what to plant when in Kirkland, Washington — is derived from the closest NOAA station with complete climate normals.

With about 260 frost-free days, Kirkland supports back-to-back plantings; stagger sowings every few weeks to keep beds productive spring through fall. Zone 9a is warm enough that Kirkland can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.

Station · SEATTLE SAND PT WSFO · 4.0 km
Last spring frost
March 8
50% chance · 32°F
First fall frost
November 23
50% chance · 32°F
Growing season
260 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for KirklandA year-band showing 32°F frost risk from January to December for Kirkland: last spring frost around March 8, first fall frost around November 23, about 260 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

Frost probability

SEATTLE SAND PT WSFO · 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 Kirkland’s own odds, recorded at SEATTLE SAND PT WSFO.

Frost-probability curves for KirklandProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around March 8 and the first fall frost around November 23, giving about 260 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 26Apr 4Mar 17Oct 24Nov 5Nov 22
32°FMar 29Mar 8Feb 13Nov 4Nov 23Dec 16
28°FMar 1Feb 11Dec 27Nov 17Dec 11Jan 17

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 15 days
Brussels Sprouts
August 3August 17

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

Nearby weather stations

3 within 23 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.

SEATTLE SAND PT WSFO
Primary
4 km · 18 m elevation
SPRING
Mar 8
FALL
Nov 23
SEATTLE BOEING FLD
20 km · 6 m elevation
SPRING
Mar 13
FALL
Nov 17
RENTON MUNI AP
23 km · 9 m elevation
SPRING
Mar 13
FALL
Nov 16

Kirkland planting FAQ

When is the last spring frost in Kirkland, WA?

On average, the last spring frost in Kirkland is around March 8 (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 Kirkland, WA?

In Kirkland, the first 32°F freeze of fall lands around November 23 on average. Time your last harvests and any season-extension cover before it.

What hardiness zone is Kirkland in?

Kirkland is in USDA hardiness zone 9a. In zone 9a, winters are mild — many tender perennials overwinter here.

How long is the growing season in Kirkland?

There are roughly 260 frost-free days in Kirkland (a long growing season), running from the average last frost around March 8 to the first fall frost near November 23.

When should I plant tomatoes in Kirkland?

In Kirkland, start tomato seeds indoors around January 11–January 25, then transplant seedlings outdoors around March 15 once the danger of frost has passed.

Planting reminders

Never miss a window in Kirkland

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

Nearby cities

8 within reach

Frost dates recorded at SEATTLE SAND PT WSFO, 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 Kirkland, WA — Frost Dates & Zone 9a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00094290. Retrieved from https://blissgarden.com/washington/kirkland.
When to Plant in Kirkland, WA — Frost Dates & Zone 9a — BlissGarden