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

Planting zone for 98624 — Ilwaco, WA

ZIP code 98624 (Ilwaco, Pacific County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is April 6 and the first fall frost October 26.

Where ZIP 98624 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 frostApr 6

First frostOct 26

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 Ilwaco, 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 Ilwaco, WA

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostApril 6median — 50% chance of a later frost

Safe for tender plantsApril 28only 10% chance of frost after

First fall frostOctober 26median — 10% chance by Oct 4

Growing season200 daysfrost-free, median

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

From the NOAA station Long Beach Exp Stn, WA — 4 miles away, elevation 26 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 98624

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 23 – Mar 9

SpinachSow outdoors · Feb 23 – Mar 16

Broccoli, cabbageStart indoors · Jan 26 – Feb 9

Broccoli, cabbageTransplant · Mar 16 – Mar 30

Onion setsPlant outdoors · Mar 9 – Mar 23

PotatoesPlant outdoors · Mar 16 – Mar 30

LettuceSow outdoors · Mar 9 – Mar 23

Carrots, beetsSow outdoors · Mar 16 – Mar 30

TomatoesStart indoors · Feb 9 – Feb 23

TomatoesTransplant · Apr 13 – Apr 27

Peppers, eggplantStart indoors · Jan 26 – Feb 9

Peppers, eggplantTransplant · Apr 20 – May 4

BeansSow outdoors · Apr 13 – Apr 27

Sweet cornSow outdoors · Apr 13 – Apr 27

Cucumbers, squashSow outdoors · Apr 13 – Apr 27

Fall lettuce, spinachSow outdoors · Aug 31 – Sep 14

GarlicPlant cloves · Oct 12 – Nov 16

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 6) and first fall frost (Oct 26) 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 98624 came on Feb 16 — about the same time as the 1991–2020 average (Feb 14).

average
Feb 142026
Feb 16

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 Ilwaco, WA.

Soil in Ilwaco, WA

The soil mapped at the center of ZIP 98624 is Vesta — silt loam, well drained.

TextureSilt loama good balance for most vegetables

pH5.6moderately acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter12.5%high

Hydrologic groupBwater soaks in moderately

Farmland classprime farmlandUSDA classification

Map unit: Vesta silt loam, 1 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 98624; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Ilwaco, WA

Summer high67 °Faverage high, August

Winter low35 °Faverage low, February

Hot days0days a year at 90 °F or more

Freezing nights41nights a year at 32 °F or less

Growing degree days1,140base 50 °F — the season’s usable heat

Longest day15 h 48 mindaylight on June 21

Shortest day8 h 36 mindaylight on December 21

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

Precipitation78.5 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: Long Beach Exp Stn, WA (4 mi away); precipitation: Long Beach Exp Stn, WA (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

3 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

986148b

Chinook, WA · 4 mi

986319a

Long Beach, WA · 4 mi

Warrenton, OR · 15 mi

986438b

Rosburg, WA · 15 mi

Washington planting zones →

Questions about 98624

What planting zone is ZIP code 98624?

ZIP code 98624 (Ilwaco, 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 Ilwaco, WA?

The median last spring frost (32 °F) near 98624 is April 6; after April 28 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Long Beach Exp Stn station.

When is the first frost in Ilwaco, WA?

The median first fall frost near 98624 is October 26, giving a median frost-free growing season of 200 days.

When should I plant tomatoes in 98624?

Start tomato seeds indoors around Feb 9 – Feb 23 and set transplants outside around Apr 13 – Apr 27, one to three weeks after the median last frost.

How much rain and snow does 98624 get?

About 78.5 inches of precipitation a year (NOAA 1991–2020 normals, Long Beach Exp Stn station).

How hot do summers get in Ilwaco, WA?

The average high peaks at 67 °F in August, with about 0 days a year at 90 °F or more.

What kind of soil does 98624 have?

The USDA soil survey maps Vesta at the center of ZIP 98624: silt loam, well drained, pH about 5.6 (moderately acidic).

Did spring come early in Ilwaco, WA in 2026?

Spring leaf-out near 98624 came on Feb 16 in 2026, about the same as the 1991–2020 average (Feb 14), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Ilwaco, WA?

Long-day onions: the longest day near 98624 is 15 h 48 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 98624 change?

Yes. The 2012 USDA map put 98624 in zone 8b; the 2023 map puts it in zone 9a. The newer map uses 1991–2020 data and more weather stations.