Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 30, 2026

Planting zone for 98651 — Underwood, WA

ZIP code 98651 (Underwood, Skamania County) is in USDA zone 8a: the coldest winter night averages 10 to 15 °F. The median last spring frost is April 20 and the first fall frost October 13.

Where ZIP 98651 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.

Zone8a10 to 15 °F

Coldest night−12.2 to −9.4 °C

Last frostApr 20

First frostOct 13

2012 zone7b

Was 7b 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 8a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Underwood, 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 Underwood, WA

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 20median — 50% chance of a later frost

Safe for tender plantsMay 9only 10% chance of frost after

First fall frostOctober 13median — 10% chance by Sep 30

Growing season177 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 20 and returns around October 28.

From the NOAA station Hood Rvr Exp Stn, OR — 5 miles away, elevation 499 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 98651

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 9 – Mar 23

SpinachSow outdoors · Mar 9 – Mar 30

Broccoli, cabbageStart indoors · Feb 9 – Feb 23

Broccoli, cabbageTransplant · Mar 30 – Apr 13

Onion setsPlant outdoors · Mar 23 – Apr 6

PotatoesPlant outdoors · Mar 30 – Apr 13

LettuceSow outdoors · Mar 23 – Apr 6

Carrots, beetsSow outdoors · Mar 30 – Apr 13

TomatoesStart indoors · Feb 23 – Mar 9

TomatoesTransplant · Apr 27 – May 11

Peppers, eggplantStart indoors · Feb 9 – Feb 23

Peppers, eggplantTransplant · May 4 – May 18

BeansSow outdoors · Apr 27 – May 11

Sweet cornSow outdoors · Apr 27 – May 11

Cucumbers, squashSow outdoors · Apr 27 – May 11

Fall lettuce, spinachSow outdoors · Aug 18 – Sep 1

GarlicPlant cloves · Sep 29 – Nov 3

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 20) and first fall frost (Oct 13) 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 98651 came on Mar 20 — 12 days earlier than the 1991–2020 average (Apr 1).

average
Apr 12026
Mar 20

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 8a in Washington

611 plants native to the lower 48 states, recorded in Washington, and rated by the USDA to survive 10 °F or colder — the bottom of zone 8a. 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 Underwood, WA.

Soil in Underwood, WA

The soil mapped at the center of ZIP 98651 is Undusk — gravelly loam, well drained.

TextureGravelly loama good balance for most vegetables

pH6.7neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter1.5%low — add compost

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Undusk gravelly loam, 30 to 65 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 98651; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Underwood, WA

Summer high82 °Faverage high, July

Winter low30 °Faverage low, January

Hot days21days a year at 90 °F or more

Freezing nights92nights a year at 32 °F or less

Growing degree days2,282base 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)

Precipitation36.7 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: Hood Rvr Exp Stn, OR (5 mi away); precipitation: Hood River 0.8 Sw, OR (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

White Salmon, WA · 8 mi

970317b

Hood River, OR · 9 mi

970148a

Cascade Locks, OR · 12 mi

970407b

Mosier, OR · 13 mi

986507a

Trout Lake, WA · 14 mi

986027a

Appleton, WA · 17 mi

Washington planting zones →

Questions about 98651

What planting zone is ZIP code 98651?

ZIP code 98651 (Underwood, WA) is in USDA hardiness zone 8a on the 2023 map: the coldest night of an average winter reaches 10 to 15 °F (−12.2 to −9.4 °C).

When is the last frost in Underwood, WA?

The median last spring frost (32 °F) near 98651 is April 20; after May 9 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Hood Rvr Exp Stn station.

When is the first frost in Underwood, WA?

The median first fall frost near 98651 is October 13, giving a median frost-free growing season of 177 days.

When should I plant tomatoes in 98651?

Start tomato seeds indoors around Feb 23 – Mar 9 and set transplants outside around Apr 27 – May 11, one to three weeks after the median last frost.

How much rain and snow does 98651 get?

About 36.7 inches of precipitation a year (NOAA 1991–2020 normals, Hood River 0.8 Sw station).

How hot do summers get in Underwood, WA?

The average high peaks at 82 °F in July, with about 21 days a year at 90 °F or more.

What kind of soil does 98651 have?

The USDA soil survey maps Undusk at the center of ZIP 98651: gravelly loam, well drained, pH about 6.7 (neutral).

Did spring come early in Underwood, WA in 2026?

Spring leaf-out near 98651 came on Mar 20 in 2026, 12 days earlier than the 1991–2020 average (Apr 1), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Underwood, WA?

Long-day onions: the longest day near 98651 is 15 h 43 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 98651 change?

Yes. The 2012 USDA map put 98651 in zone 7b; the 2023 map puts it in zone 8a. The newer map uses 1991–2020 data and more weather stations.