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

Planting zone for 98555 — Lilliwaup, WA

ZIP code 98555 (Lilliwaup, Mason County) is in USDA zone 8b: the coldest winter night averages 15 to 20 °F. The median last spring frost is March 24 and the first fall frost November 15.

Where ZIP 98555 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.

Zone8b15 to 20 °F

Coldest night−9.4 to −6.7 °C

Last frostMar 24

First frostNov 15

2012 zone8a

Was 8a 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 8b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Lilliwaup, 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 Lilliwaup, WA

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMarch 24median — 50% chance of a later frost

Safe for tender plantsApril 17only 10% chance of frost after

First fall frostNovember 15median — 10% chance by Oct 25

Growing season235 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 20 and returns around December 7.

From the NOAA station Cushman Powerhouse #2, WA — 12 miles away, elevation 20 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 98555

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 10 – Feb 24

SpinachSow outdoors · Feb 10 – Mar 3

Broccoli, cabbageStart indoors · Jan 13 – Jan 27

Broccoli, cabbageTransplant · Mar 3 – Mar 17

Onion setsPlant outdoors · Feb 24 – Mar 10

PotatoesPlant outdoors · Mar 3 – Mar 17

LettuceSow outdoors · Feb 24 – Mar 10

Carrots, beetsSow outdoors · Mar 3 – Mar 17

TomatoesStart indoors · Jan 27 – Feb 10

TomatoesTransplant · Mar 31 – Apr 14

Peppers, eggplantStart indoors · Jan 13 – Jan 27

Peppers, eggplantTransplant · Apr 7 – Apr 21

BeansSow outdoors · Mar 31 – Apr 14

Sweet cornSow outdoors · Mar 31 – Apr 14

Cucumbers, squashSow outdoors · Mar 31 – Apr 14

Fall lettuce, spinachSow outdoors · Sep 20 – Oct 4

GarlicPlant cloves · Nov 1 – Dec 6

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 24) and first fall frost (Nov 15) 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 98555 came on Feb 18 — 15 days earlier than the 1991–2020 average (Mar 5).

average
Mar 52026
Feb 18

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 8b in Washington

614 plants native to the lower 48 states, recorded in Washington, and rated by the USDA to survive 15 °F or colder — the bottom of zone 8b. 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 Lilliwaup, WA.

Soil in Lilliwaup, WA

The soil mapped at the center of ZIP 98555 is Grove — cobbly sandy loam, somewhat excessively drained.

TextureCobbly sandy loamdrains and warms fast; dries out and needs more feeding

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

DrainageSomewhat excessively drainednatural drainage class

Organic matter7.5%high

Hydrologic groupAwater soaks in fast

Farmland classNot prime farmlandUSDA classification

Map unit: Grove cobbly sandy loam, 5 to 15 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 98555; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Lilliwaup, WA

Summer high76 °Faverage high, July

Winter low35 °Faverage low, February

Hot days2days a year at 90 °F or more

Freezing nights46nights a year at 32 °F or less

Growing degree days1,831base 50 °F — the season’s usable heat

Longest day15 h 59 mindaylight on June 21

Shortest day8 h 26 mindaylight on December 21

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

Precipitation92 inper year, rain and melted snow

Snowfall4 inper year; 2 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Cushman Powerhouse #2, WA (12 mi away); precipitation: Cushman Powerhouse #2, WA (12 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 8b.

Bremerton, WA · 14 mi

985248b

Allyn, WA · 16 mi

Washington planting zones →

Questions about 98555

What planting zone is ZIP code 98555?

ZIP code 98555 (Lilliwaup, WA) is in USDA hardiness zone 8b on the 2023 map: the coldest night of an average winter reaches 15 to 20 °F (−9.4 to −6.7 °C).

When is the last frost in Lilliwaup, WA?

The median last spring frost (32 °F) near 98555 is March 24; after April 17 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Cushman Powerhouse #2 station.

When is the first frost in Lilliwaup, WA?

The median first fall frost near 98555 is November 15, giving a median frost-free growing season of 235 days.

When should I plant tomatoes in 98555?

Start tomato seeds indoors around Jan 27 – Feb 10 and set transplants outside around Mar 31 – Apr 14, one to three weeks after the median last frost.

How much rain and snow does 98555 get?

About 92 inches of precipitation a year and 4 inches of snowfall (NOAA 1991–2020 normals, Cushman Powerhouse #2 station).

How hot do summers get in Lilliwaup, WA?

The average high peaks at 76 °F in July, with about 2 days a year at 90 °F or more.

What kind of soil does 98555 have?

The USDA soil survey maps Grove at the center of ZIP 98555: cobbly sandy loam, somewhat excessively drained, pH about 5.6 (moderately acidic).

Did spring come early in Lilliwaup, WA in 2026?

Spring leaf-out near 98555 came on Feb 18 in 2026, 15 days earlier than the 1991–2020 average (Mar 5), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Lilliwaup, WA?

Long-day onions: the longest day near 98555 is 15 h 59 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 98555 change?

Yes. The 2012 USDA map put 98555 in zone 8a; the 2023 map puts it in zone 8b. The newer map uses 1991–2020 data and more weather stations.