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

Planting zone for 98952 — White Swan, WA

ZIP code 98952 (White Swan, Yakima County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 21 and the first fall frost October 15.

Where ZIP 98952 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.

Zone7a0 to 5 °F

Coldest night−17.8 to −15 °C

Last frostApr 21

First frostOct 15

2012 zone6b

Was 6b 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 7a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for White Swan, 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 White Swan, WA

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 21median — 50% chance of a later frost

Safe for tender plantsMay 7only 10% chance of frost after

First fall frostOctober 15median — 10% chance by Oct 4

Growing season176 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 31 and returns around October 26.

From the NOAA station Wapato, WA — 20 miles away, elevation 840 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 98952

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 10 – Mar 24

SpinachSow outdoors · Mar 10 – Mar 31

Broccoli, cabbageStart indoors · Feb 10 – Feb 24

Broccoli, cabbageTransplant · Mar 31 – Apr 14

Onion setsPlant outdoors · Mar 24 – Apr 7

PotatoesPlant outdoors · Mar 31 – Apr 14

LettuceSow outdoors · Mar 24 – Apr 7

Carrots, beetsSow outdoors · Mar 31 – Apr 14

TomatoesStart indoors · Feb 24 – Mar 10

TomatoesTransplant · Apr 28 – May 12

Peppers, eggplantStart indoors · Feb 10 – Feb 24

Peppers, eggplantTransplant · May 5 – May 19

BeansSow outdoors · Apr 28 – May 12

Sweet cornSow outdoors · Apr 28 – May 12

Cucumbers, squashSow outdoors · Apr 28 – May 12

Fall lettuce, spinachSow outdoors · Aug 20 – Sep 3

GarlicPlant cloves · Oct 1 – Nov 5

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 21) and first fall frost (Oct 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 98952 came on Mar 17 — 9 days earlier than the 1991–2020 average (Mar 26).

average
Mar 262026
Mar 17

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 7a in Washington

590 plants native to the lower 48 states, recorded in Washington, and rated by the USDA to survive 0 °F or colder — the bottom of zone 7a. 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 White Swan, WA.

Soil in White Swan, WA

The soil mapped at the center of ZIP 98952 is Simcoe — silt loam, well drained.

TextureSilt loama good balance for most vegetables

pH7.0neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter1.5%low — add compost

Hydrologic groupCwater soaks in slowly

Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Simcoe silt loam, 0 to 2 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 98952; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in White Swan, WA

Summer high90 °Faverage high, July

Winter low23 °Faverage low, December

Hot days41days a year at 90 °F or more

Freezing nights127nights a year at 32 °F or less

Growing degree days3,018base 50 °F — the season’s usable heat

Longest day15 h 48 mindaylight on June 21

Shortest day8 h 35 mindaylight on December 21

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

Precipitation31.7 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: Wapato, WA (20 mi away); precipitation: Lost Horse, WA (12 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7a.

989337a

Harrah, WA · 9 mi

989207a

Brownstown, WA · 11 mi

Washington planting zones →

Questions about 98952

What planting zone is ZIP code 98952?

ZIP code 98952 (White Swan, WA) is in USDA hardiness zone 7a on the 2023 map: the coldest night of an average winter reaches 0 to 5 °F (−17.8 to −15 °C).

When is the last frost in White Swan, WA?

The median last spring frost (32 °F) near 98952 is April 21; after May 7 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Wapato station.

When is the first frost in White Swan, WA?

The median first fall frost near 98952 is October 15, giving a median frost-free growing season of 176 days.

When should I plant tomatoes in 98952?

Start tomato seeds indoors around Feb 24 – Mar 10 and set transplants outside around Apr 28 – May 12, one to three weeks after the median last frost.

How much rain and snow does 98952 get?

About 31.7 inches of precipitation a year (NOAA 1991–2020 normals, Lost Horse station).

How hot do summers get in White Swan, WA?

The average high peaks at 90 °F in July, with about 41 days a year at 90 °F or more.

What kind of soil does 98952 have?

The USDA soil survey maps Simcoe at the center of ZIP 98952: silt loam, well drained, pH about 7.0 (neutral).

Did spring come early in White Swan, WA in 2026?

Spring leaf-out near 98952 came on Mar 17 in 2026, 9 days earlier than the 1991–2020 average (Mar 26), according to the USA National Phenology Network Spring Index.

What kind of onions grow in White Swan, WA?

Long-day onions: the longest day near 98952 is 15 h 48 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 98952 change?

Yes. The 2012 USDA map put 98952 in zone 6b; the 2023 map puts it in zone 7a. The newer map uses 1991–2020 data and more weather stations.