Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated

Planting zone for Lynnwood, WA

Lynnwood, WA is in USDA zone 9a across its 4 ZIP codes. The median last spring frost is March 9 and the first fall frost November 17.

Lynnwood on the zone map

Outlined: its 3 ZIP code areas · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone9a20 to 25 °F
ZIP codes4
Last frostMar 9
First frostNov 17
Growing season250 days

9a 4 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

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Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in Lynnwood, WA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMarch 9median — 50% chance of a later frost
Safe for tender plantsMarch 29only 10% chance of frost after
First fall frostNovember 17median — 10% chance by Oct 31
Growing season250 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 13 and returns around December 6.

From the NOAA station Everett Snohomish Airport, WA, elevation 607 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in Lynnwood

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Jan 26 – Feb 9
SpinachSow outdoors · Jan 26 – Feb 16
Broccoli, cabbageStart indoors · Dec 29 – Jan 12
Broccoli, cabbageTransplant · Feb 16 – Mar 2
Onion setsPlant outdoors · Feb 9 – Feb 23
PotatoesPlant outdoors · Feb 16 – Mar 2
LettuceSow outdoors · Feb 9 – Feb 23
Carrots, beetsSow outdoors · Feb 16 – Mar 2
TomatoesStart indoors · Jan 12 – Jan 26
TomatoesTransplant · Mar 16 – Mar 30
Peppers, eggplantStart indoors · Dec 29 – Jan 12
Peppers, eggplantTransplant · Mar 23 – Apr 6
BeansSow outdoors · Mar 16 – Mar 30
Sweet cornSow outdoors · Mar 16 – Mar 30
Cucumbers, squashSow outdoors · Mar 16 – Mar 30
Fall lettuce, spinachSow outdoors · Sep 22 – Oct 6
GarlicPlant cloves · Nov 3 – Dec 8
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 9) and first fall frost (Nov 17) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 98037 came on Feb 16 — 4 days earlier than the 1991–2020 average (Feb 20).

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Native plants for zone 9a in Washington

617 plants native to the lower 48 states, recorded in Washington, and rated by the USDA to survive 20 °F or colder — the bottom of zone 9a. Each links to its USDA PLANTS profile.

Trees 32

Alaska cedar75 ft · blooms mid spring · low shade tolerance · to −22 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Fbalsam poplar80 ft · blooms late spring · high shade tolerance · to −79 °Fbigleaf maple60 ft · blooms mid spring · medium shade tolerance · to −14 °Fblack locust60 ft · blooms spring · high shade tolerance · to −37 °Fboxelder60 ft · blooms early spring · low shade tolerance · to −46 °F

Shrubs 115

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falpine laurel1 ft · blooms late spring · low shade tolerance · to −28 °FAmerican plum24 ft · blooms mid spring · high shade tolerance · to −38 °Fantelope bitterbrush6 ft · blooms early spring · medium shade tolerance · to −36 °FBarclay's willow15 ft · high shade tolerance · to −43 °F

Wildflowers & perennials 293

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °Falpine mountainsorrel1 ft · blooms mid summer · medium shade tolerance · to −43 °FAmerican alpine speedwell1 ft · blooms summer · medium shade tolerance · to −28 °FAmerican bistort1.5 ft · blooms mid spring · high shade tolerance · to −38 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °F

Grasses 159

Alaska brome5 ft · blooms late spring · low shade tolerance · to −18 °FAlaska oniongrass3 ft · blooms mid spring · low shade tolerance · to −33 °Falkali cordgrass3 ft · blooms late summer · high shade tolerance · to −38 °Falkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °Falpine timothy1.4 ft · blooms late spring · medium shade tolerance · to −43 °FAmerican beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °F

Vines 3

riverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Ftrumpet creeper2 ft · blooms summer · high shade tolerance · to −13 °Fwestern white clematis1 ft · blooms mid summer · medium shade tolerance · to −38 °F

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Lynnwood, WA.

Soil in Lynnwood, WA

The soil mapped at the center of ZIP 98037 is Alderwood — gravelly ashy sandy loam, moderately well drained.

TextureGravelly ashy sandy loamdrains and warms fast; dries out and needs more feeding
pH5.8moderately acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter6.5%high
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Alderwood-Urban land complex, 2 to 8 percent slopes.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 98037; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Lynnwood, WA

Summer high73 °Faverage high, August
Winter low36 °Faverage low, December
Hot days1days a year at 90 °F or more
Freezing nights29nights a year at 32 °F or less
Growing degree days1,771base 50 °F — the season’s usable heat
Longest day16 h 01 mindaylight on June 21
Shortest day8 h 23 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation45.2 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°32 °FJanuary: average high 46 °F, low 37 °F 46°37° JanFebruary: average high 48 °F, low 37 °F 48°37° FebMarch: average high 52 °F, low 39 °F 52°39° MarApril: average high 56 °F, low 43 °F 56°43° AprMay: average high 63 °F, low 48 °F 63°48° MayJune: average high 66 °F, low 51 °F 66°51° JunJuly: average high 72 °F, low 55 °F 72°55° JulAugust: average high 73 °F, low 55 °F 73°55° AugSeptember: average high 68 °F, low 52 °F 68°52° SepOctober: average high 58 °F, low 46 °F 58°46° OctNovember: average high 50 °F, low 40 °F 50°40° NovDecember: average high 45 °F, low 36 °F 45°36° Dec

Precipitation by month inches

0″2″4″6″8″January: 5.68 in precipitation 5.7 JanFebruary: 3.94 in precipitation 3.9 FebMarch: 4.40 in precipitation 4.4 MarApril: 4.24 in precipitation 4.2 AprMay: 2.77 in precipitation 2.8 MayJune: 2.04 in precipitation 2.0 JunJuly: 1.24 in precipitation 1.2 JulAugust: 1.25 in precipitation 1.3 AugSeptember: 2.55 in precipitation 2.5 SepOctober: 3.84 in precipitation 3.8 OctNovember: 7.14 in precipitation 7.1 NovDecember: 6.07 in precipitation 6.1 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Everett Snohomish Airport, WA (5 mi away); precipitation: Bothell 5.4 N, WA (4 mi away). Daylight is calculated from latitude.

ZIP codes in Lynnwood

980369a
20 to 25 °F
980379a
20 to 25 °F
980469a
20 to 25 °F
980879a
20 to 25 °F

Washington planting zones →

Questions about Lynnwood

What planting zone is Lynnwood, WA?

Lynnwood, WA is in USDA hardiness zone 9a on the 2023 map (9a: 20 to 25 °F).

When is the last frost in Lynnwood, WA?

The median last spring frost is March 9 and the median first fall frost is November 17 (NOAA 1991–2020 normals, Everett Snohomish Airport station).

When can I plant a garden in Lynnwood, WA?

Cool-season crops like peas and spinach go in around Jan 26 – Feb 16; tomatoes, peppers, beans and squash after about Mar 16, once frost risk has passed.

What kind of onions grow in Lynnwood, WA?

Long-day onions: the longest day is 16 h 01 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

How much rain and snow does Lynnwood, WA get?

About 45.2 inches of precipitation a year (NOAA 1991–2020 normals).