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

Planting zone for 98323 — Carbonado, WA

ZIP code 98323 (Carbonado, Pierce County) is in USDA zone 8b: the coldest winter night averages 15 to 20 °F. The median last spring frost is April 18 and the first fall frost October 31.

Where ZIP 98323 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 frostApr 18

First frostOct 31

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 Carbonado, 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 Carbonado, WA

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 18median — 50% chance of a later frost

Safe for tender plantsMay 10only 10% chance of frost after

First fall frostOctober 31median — 10% chance by Oct 8

Growing season196 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 15 and returns around November 17.

From the NOAA station Mud Mtn Dam, WA — 11 miles away, elevation 1,309 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 98323

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 7 – Mar 21

SpinachSow outdoors · Mar 7 – Mar 28

Broccoli, cabbageStart indoors · Feb 7 – Feb 21

Broccoli, cabbageTransplant · Mar 28 – Apr 11

Onion setsPlant outdoors · Mar 21 – Apr 4

PotatoesPlant outdoors · Mar 28 – Apr 11

LettuceSow outdoors · Mar 21 – Apr 4

Carrots, beetsSow outdoors · Mar 28 – Apr 11

TomatoesStart indoors · Feb 21 – Mar 7

TomatoesTransplant · Apr 25 – May 9

Peppers, eggplantStart indoors · Feb 7 – Feb 21

Peppers, eggplantTransplant · May 2 – May 16

BeansSow outdoors · Apr 25 – May 9

Sweet cornSow outdoors · Apr 25 – May 9

Cucumbers, squashSow outdoors · Apr 25 – May 9

Fall lettuce, spinachSow outdoors · Sep 5 – Sep 19

GarlicPlant cloves · Oct 17 – Nov 21

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 18) and first fall frost (Oct 31) 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 98323 came on Apr 3 — 13 days later than the 1991–2020 average (Mar 21).

average
Mar 212026
Apr 3

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 Carbonado, WA.

Soil in Carbonado, WA

The soil mapped at the center of ZIP 98323 is Tusip — sandy loam, well drained.

TextureSandy loamdrains and warms fast; dries out and needs more feeding

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

DrainageWell drainednatural drainage class

Organic matter12.5%high

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Tusip sandy loam, 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 98323; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Carbonado, WA

Summer high76 °Faverage high, August

Winter low33 °Faverage low, January

Hot days3days a year at 90 °F or more

Freezing nights79nights a year at 32 °F or less

Growing degree days1,654base 50 °F — the season’s usable heat

Longest day15 h 54 mindaylight on June 21

Shortest day8 h 30 mindaylight on December 21

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

Precipitation59.3 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: Mud Mtn Dam, WA (11 mi away); precipitation: Mowich, WA (4 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.

983528b

Sumner, WA · 8 mi

983987a

Paradise Inn, WA · 8 mi

Eatonville, WA · 12 mi

983858b

South Prairie, WA · 12 mi

983218b

Buckley, WA · 13 mi

Washington planting zones →

Questions about 98323

What planting zone is ZIP code 98323?

ZIP code 98323 (Carbonado, 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 Carbonado, WA?

The median last spring frost (32 °F) near 98323 is April 18; after May 10 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Mud Mtn Dam station.

When is the first frost in Carbonado, WA?

The median first fall frost near 98323 is October 31, giving a median frost-free growing season of 196 days.

When should I plant tomatoes in 98323?

Start tomato seeds indoors around Feb 21 – Mar 7 and set transplants outside around Apr 25 – May 9, one to three weeks after the median last frost.

How much rain and snow does 98323 get?

About 59.3 inches of precipitation a year (NOAA 1991–2020 normals, Mowich station).

How hot do summers get in Carbonado, WA?

The average high peaks at 76 °F in August, with about 3 days a year at 90 °F or more.

What kind of soil does 98323 have?

The USDA soil survey maps Tusip at the center of ZIP 98323: sandy loam, well drained, pH about 5.6 (moderately acidic).

Did spring come early in Carbonado, WA in 2026?

Spring leaf-out near 98323 came on Apr 3 in 2026, 13 days later than the 1991–2020 average (Mar 21), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Carbonado, WA?

Long-day onions: the longest day near 98323 is 15 h 54 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 98323 change?

Yes. The 2012 USDA map put 98323 in zone 8a; the 2023 map puts it in zone 8b. The newer map uses 1991–2020 data and more weather stations.