Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 98020 — Edmonds, WA

ZIP code 98020 (Edmonds, Snohomish County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is March 9 and the first fall frost November 17.

Where ZIP 98020 is

Outlined: the ZIP code area · 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

Coldest night−6.7 to −3.9 °C

Last frostMar 9

First frostNov 17

2012 zone8b

Was 8b on the 2012 map — half a zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 9a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Edmonds, WA…

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 Edmonds, 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 — 9 miles away, 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 98020

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 98020 came on Feb 13 — 4 days earlier than the 1991–2020 average (Feb 17).

average
Feb 172026
Feb 13

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.

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 Edmonds, WA.

Soil in Edmonds, WA

The soil mapped at the center of ZIP 98020 is Everett — slightly decomposed plant material, somewhat excessively drained.

TextureSlightly decomposed plant materialtop layer

pH4.5strongly acidic; most vegetables like 6.0–7.0

DrainageSomewhat excessively drainednatural drainage class

Organic matter75%high

Hydrologic groupAwater soaks in fast

Farmland classFarmland of statewide importanceUSDA classification

Map unit: Everett very gravelly sandy loam, 0 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 98020; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Edmonds, 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 24 mindaylight on December 21

Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)

Precipitation37.3 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Everett Snohomish Airport, WA (9 mi away); precipitation: Kingston 2.7 Sse, WA (5 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 9a.

Mountlake Terrace, WA · 3 mi

All 2 ZIP codes in Edmonds → · Washington planting zones →

Questions about 98020

What planting zone is ZIP code 98020?

ZIP code 98020 (Edmonds, WA) is in USDA hardiness zone 9a on the 2023 map: the coldest night of an average winter reaches 20 to 25 °F (−6.7 to −3.9 °C).

When is the last frost in Edmonds, WA?

The median last spring frost (32 °F) near 98020 is March 9; after March 29 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Everett Snohomish Airport station.

When is the first frost in Edmonds, WA?

The median first fall frost near 98020 is November 17, giving a median frost-free growing season of 250 days.

When should I plant tomatoes in 98020?

Start tomato seeds indoors around Jan 12 – Jan 26 and set transplants outside around Mar 16 – Mar 30, one to three weeks after the median last frost.

How much rain and snow does 98020 get?

About 37.3 inches of precipitation a year (NOAA 1991–2020 normals, Kingston 2.7 Sse station).

How hot do summers get in Edmonds, WA?

The average high peaks at 73 °F in August, with about 1 days a year at 90 °F or more.

What kind of soil does 98020 have?

The USDA soil survey maps Everett at the center of ZIP 98020: slightly decomposed plant material, somewhat excessively drained, pH about 4.5 (strongly acidic).

Did spring come early in Edmonds, WA in 2026?

Spring leaf-out near 98020 came on Feb 13 in 2026, 4 days earlier than the 1991–2020 average (Feb 17), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Edmonds, WA?

Long-day onions: the longest day near 98020 is 16 h 01 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 98020 change?

Yes. The 2012 USDA map put 98020 in zone 8b; the 2023 map puts it in zone 9a. The newer map uses 1991–2020 data and more weather stations.