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

Planting zone for 98378 — Retsil, WA

ZIP code 98378 (Retsil, Kitsap County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is March 29 and the first fall frost November 14.

Where ZIP 98378 is

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 29

First frostNov 14

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 Retsil, 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 Retsil, WA

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMarch 29median — 50% chance of a later frost

Safe for tender plantsApril 24only 10% chance of frost after

First fall frostNovember 14median — 10% chance by Oct 26

Growing season227 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 27 and returns around November 30.

From the NOAA station Bremerton, WA — 4 miles away, elevation 112 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 98378

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 15 – Mar 1

SpinachSow outdoors · Feb 15 – Mar 8

Broccoli, cabbageStart indoors · Jan 18 – Feb 1

Broccoli, cabbageTransplant · Mar 8 – Mar 22

Onion setsPlant outdoors · Mar 1 – Mar 15

PotatoesPlant outdoors · Mar 8 – Mar 22

LettuceSow outdoors · Mar 1 – Mar 15

Carrots, beetsSow outdoors · Mar 8 – Mar 22

TomatoesStart indoors · Feb 1 – Feb 15

TomatoesTransplant · Apr 5 – Apr 19

Peppers, eggplantStart indoors · Jan 18 – Feb 1

Peppers, eggplantTransplant · Apr 12 – Apr 26

BeansSow outdoors · Apr 5 – Apr 19

Sweet cornSow outdoors · Apr 5 – Apr 19

Cucumbers, squashSow outdoors · Apr 5 – Apr 19

Fall lettuce, spinachSow outdoors · Sep 19 – Oct 3

GarlicPlant cloves · Oct 31 – Dec 5

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 29) and first fall frost (Nov 14) 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 98378 came on Feb 13 — 6 days earlier than the 1991–2020 average (Feb 19).

average
Feb 192026
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 Retsil, WA.

Soil in Retsil, WA

The soil mapped at the center of ZIP 98378 is Indianola — slightly decomposed plant material, somewhat excessively drained.

TextureSlightly decomposed plant materialtop layer

pH5.5moderately 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: Indianola loamy sand, 15 to 30 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 98378; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Retsil, WA

Summer high77 °Faverage high, July

Winter low35 °Faverage low, February

Hot days4days a year at 90 °F or more

Freezing nights42nights a year at 32 °F or less

Growing degree days2,058base 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)

Precipitation45.2 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: Bremerton, WA (4 mi away); precipitation: Bremerton 1.8 Ne, WA (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

983669a

Port Orchard, WA · 2 mi

South Colby, WA · 4 mi

983539a

Manchester, WA · 6 mi

983869a

Southworth, WA · 6 mi

Washington planting zones →

Questions about 98378

What planting zone is ZIP code 98378?

ZIP code 98378 (Retsil, 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 Retsil, WA?

The median last spring frost (32 °F) near 98378 is March 29; after April 24 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Bremerton station.

When is the first frost in Retsil, WA?

The median first fall frost near 98378 is November 14, giving a median frost-free growing season of 227 days.

When should I plant tomatoes in 98378?

Start tomato seeds indoors around Feb 1 – Feb 15 and set transplants outside around Apr 5 – Apr 19, one to three weeks after the median last frost.

How much rain and snow does 98378 get?

About 45.2 inches of precipitation a year (NOAA 1991–2020 normals, Bremerton 1.8 Ne station).

How hot do summers get in Retsil, WA?

The average high peaks at 77 °F in July, with about 4 days a year at 90 °F or more.

What kind of soil does 98378 have?

The USDA soil survey maps Indianola at the center of ZIP 98378: slightly decomposed plant material, somewhat excessively drained, pH about 5.5 (moderately acidic).

Did spring come early in Retsil, WA in 2026?

Spring leaf-out near 98378 came on Feb 13 in 2026, 6 days earlier than the 1991–2020 average (Feb 19), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Retsil, WA?

Long-day onions: the longest day near 98378 is 15 h 59 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 98378 change?

Yes. The 2012 USDA map put 98378 in zone 8b; the 2023 map puts it in zone 9a. The newer map uses 1991–2020 data and more weather stations.