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

Planting zone for 98606 — Brush Prairie, WA

ZIP code 98606 (Brush Prairie, Clark County) is in USDA zone 8b: the coldest winter night averages 15 to 20 °F. The median last spring frost is April 26 and the first fall frost October 16.

Where ZIP 98606 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 26

First frostOct 16

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 Brush Prairie, 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 Brush Prairie, WA

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 26median — 50% chance of a later frost

Safe for tender plantsMay 12only 10% chance of frost after

First fall frostOctober 16median — 10% chance by Sep 29

Growing season174 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 29 and returns around November 5.

From the NOAA station Battle Ground, WA — 4 miles away, elevation 285 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 98606

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 15 – Mar 29

SpinachSow outdoors · Mar 15 – Apr 5

Broccoli, cabbageStart indoors · Feb 15 – Mar 1

Broccoli, cabbageTransplant · Apr 5 – Apr 19

Onion setsPlant outdoors · Mar 29 – Apr 12

PotatoesPlant outdoors · Apr 5 – Apr 19

LettuceSow outdoors · Mar 29 – Apr 12

Carrots, beetsSow outdoors · Apr 5 – Apr 19

TomatoesStart indoors · Mar 1 – Mar 15

TomatoesTransplant · May 3 – May 17

Peppers, eggplantStart indoors · Feb 15 – Mar 1

Peppers, eggplantTransplant · May 10 – May 24

BeansSow outdoors · May 3 – May 17

Sweet cornSow outdoors · May 3 – May 17

Cucumbers, squashSow outdoors · May 3 – May 17

Fall lettuce, spinachSow outdoors · Aug 21 – Sep 4

GarlicPlant cloves · Oct 2 – Nov 6

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 26) and first fall frost (Oct 16) 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 98606 came on Feb 22 — 6 days earlier than the 1991–2020 average (Feb 28).

average
Feb 282026
Feb 22

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 Brush Prairie, WA.

Soil in Brush Prairie, WA

The soil mapped at the center of ZIP 98606 is Hesson — clay loam, well drained.

TextureClay loamholds water and nutrients; slow to drain and warm up

pH5.3strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter2.5%moderate

Hydrologic groupCwater soaks in slowly

Farmland classprime farmlandUSDA classification

Map unit: Hesson clay 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 98606; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Brush Prairie, WA

Summer high80 °Faverage high, August

Winter low32 °Faverage low, January

Hot days11days a year at 90 °F or more

Freezing nights70nights a year at 32 °F or less

Growing degree days1,839base 50 °F — the season’s usable heat

Longest day15 h 43 mindaylight on June 21

Shortest day8 h 40 mindaylight on December 21

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

Precipitation57.8 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: Battle Ground, WA (4 mi away); precipitation: Brush Prairie 4.7 Ene, WA (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 8b.

986828b

Vancouver, WA · 4 mi

986048b

Battle Ground, WA · 6 mi

Washington planting zones →

Questions about 98606

What planting zone is ZIP code 98606?

ZIP code 98606 (Brush Prairie, 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 Brush Prairie, WA?

The median last spring frost (32 °F) near 98606 is April 26; after May 12 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Battle Ground station.

When is the first frost in Brush Prairie, WA?

The median first fall frost near 98606 is October 16, giving a median frost-free growing season of 174 days.

When should I plant tomatoes in 98606?

Start tomato seeds indoors around Mar 1 – Mar 15 and set transplants outside around May 3 – May 17, one to three weeks after the median last frost.

How much rain and snow does 98606 get?

About 57.8 inches of precipitation a year (NOAA 1991–2020 normals, Brush Prairie 4.7 Ene station).

How hot do summers get in Brush Prairie, WA?

The average high peaks at 80 °F in August, with about 11 days a year at 90 °F or more.

What kind of soil does 98606 have?

The USDA soil survey maps Hesson at the center of ZIP 98606: clay loam, well drained, pH about 5.3 (strongly acidic).

Did spring come early in Brush Prairie, WA in 2026?

Spring leaf-out near 98606 came on Feb 22 in 2026, 6 days earlier than the 1991–2020 average (Feb 28), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Brush Prairie, WA?

Long-day onions: the longest day near 98606 is 15 h 43 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 98606 change?

Yes. The 2012 USDA map put 98606 in zone 8a; the 2023 map puts it in zone 8b. The newer map uses 1991–2020 data and more weather stations.