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

Planting zone for 98953 — Zillah, WA

ZIP code 98953 (Zillah, Yakima County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is May 4 and the first fall frost October 10.

Where ZIP 98953 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 frostMay 4
First frostOct 10
2012 zone7a

Same zone as on the 2012 map. 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 Zillah, 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 Zillah, WA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 4median — 50% chance of a later frost
Safe for tender plantsMay 23only 10% chance of frost after
First fall frostOctober 10median — 10% chance by Sep 26
Growing season155 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 18 and returns around October 23.

From the NOAA station Moxee City 10 E, WA — 6 miles away, elevation 1,549 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 98953

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 23 – Apr 6
SpinachSow outdoors · Mar 23 – Apr 13
Broccoli, cabbageStart indoors · Feb 23 – Mar 9
Broccoli, cabbageTransplant · Apr 13 – Apr 27
Onion setsPlant outdoors · Apr 6 – Apr 20
PotatoesPlant outdoors · Apr 13 – Apr 27
LettuceSow outdoors · Apr 6 – Apr 20
Carrots, beetsSow outdoors · Apr 13 – Apr 27
TomatoesStart indoors · Mar 9 – Mar 23
TomatoesTransplant · May 11 – May 25
Peppers, eggplantStart indoors · Feb 23 – Mar 9
Peppers, eggplantTransplant · May 18 – Jun 1
BeansSow outdoors · May 11 – May 25
Sweet cornSow outdoors · May 11 – May 25
Cucumbers, squashSow outdoors · May 11 – May 25
Fall lettuce, spinachSow outdoors · Aug 15 – Aug 29
GarlicPlant cloves · Sep 26 – Oct 31
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 4) and first fall frost (Oct 10) 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 98953 came on Mar 8 — 13 days earlier than the 1991–2020 average (Mar 21).

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.

Trees 31

Alaska cedar75 ft · blooms mid spring · low shade tolerance · to −22 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Fbalsam poplar80 ft · blooms late spring · high shade tolerance · to −79 °Fbigleaf maple60 ft · blooms mid spring · medium shade tolerance · to −14 °Fblack locust60 ft · blooms spring · high shade tolerance · to −37 °Fboxelder60 ft · blooms early spring · low shade tolerance · to −46 °F

Shrubs 105

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falpine laurel1 ft · blooms late spring · low shade tolerance · to −28 °FAmerican plum24 ft · blooms mid spring · high shade tolerance · to −38 °Fantelope bitterbrush6 ft · blooms early spring · medium shade tolerance · to −36 °FBarclay's willow15 ft · high shade tolerance · to −43 °F

Wildflowers & perennials 282

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °Falpine mountainsorrel1 ft · blooms mid summer · medium shade tolerance · to −43 °FAmerican alpine speedwell1 ft · blooms summer · medium shade tolerance · to −28 °FAmerican bistort1.5 ft · blooms mid spring · high shade tolerance · to −38 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °F

Grasses 157

Alaska brome5 ft · blooms late spring · low shade tolerance · to −18 °FAlaska oniongrass3 ft · blooms mid spring · low shade tolerance · to −33 °Falkali cordgrass3 ft · blooms late summer · high shade tolerance · to −38 °Falkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °Falpine timothy1.4 ft · blooms late spring · medium shade tolerance · to −43 °FAmerican beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °F

Vines 3

riverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Ftrumpet creeper2 ft · blooms summer · high shade tolerance · to −13 °Fwestern white clematis1 ft · blooms mid summer · medium shade tolerance · to −38 °F

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 Zillah, WA.

Soil in Zillah, WA

The soil mapped at the center of ZIP 98953 is Scoon — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH7.9alkaline; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter0.75%low — add compost
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Scoon silt loam, 5 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 98953; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Zillah, WA

Summer high88 °Faverage high, July
Winter low24 °Faverage low, December
Hot days30days a year at 90 °F or more
Freezing nights139nights a year at 32 °F or less
Growing degree days2,458base 50 °F — the season’s usable heat
Longest day15 h 49 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)
Precipitation7.8 inper year, rain and melted snow
Snowfall10 inper year; 20 days with snow on the ground

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 38 °F, low 25 °F 38°25° JanFebruary: average high 45 °F, low 27 °F 45°27° FebMarch: average high 54 °F, low 31 °F 54°31° MarApril: average high 62 °F, low 36 °F 62°36° AprMay: average high 72 °F, low 43 °F 72°43° MayJune: average high 79 °F, low 49 °F 79°49° JunJuly: average high 88 °F, low 54 °F 88°54° JulAugust: average high 87 °F, low 54 °F 87°54° AugSeptember: average high 77 °F, low 47 °F 77°47° SepOctober: average high 62 °F, low 38 °F 62°38° OctNovember: average high 47 °F, low 30 °F 47°30° NovDecember: average high 37 °F, low 24 °F 37°24° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″January: 0.94 in precipitation, 3.2 in snowfall 0.9❄3 JanFebruary: 0.62 in precipitation, 1.2 in snowfall 0.6❄1 FebMarch: 0.61 in precipitation, 0.4 in snowfall 0.6 MarApril: 0.74 in precipitation 0.7 AprMay: 0.86 in precipitation 0.9 MayJune: 0.63 in precipitation 0.6 JunJuly: 0.22 in precipitation 0.2 JulAugust: 0.18 in precipitation 0.2 AugSeptember: 0.29 in precipitation 0.3 SepOctober: 0.83 in precipitation 0.8 OctNovember: 0.84 in precipitation, 1.7 in snowfall 0.8❄2 NovDecember: 1.08 in precipitation, 3.4 in snowfall 1.1❄3 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Moxee City 10 E, WA (6 mi away); precipitation: Moxee City 10 E, WA (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

989217a
Buena, WA · 4 mi
989367a
Moxee, WA · 7 mi
989387b
Outlook, WA · 7 mi
989327a
Granger, WA · 8 mi
989397a
Parker, WA · 12 mi
989487a
Toppenish, WA · 15 mi
989017a
Yakima, WA · 16 mi
989307b
Grandview, WA · 20 mi

Washington planting zones →

Questions about 98953

What planting zone is ZIP code 98953?

ZIP code 98953 (Zillah, 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 Zillah, WA?

The median last spring frost (32 °F) near 98953 is May 4; after May 23 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Moxee City 10 E station.

When is the first frost in Zillah, WA?

The median first fall frost near 98953 is October 10, giving a median frost-free growing season of 155 days.

When should I plant tomatoes in 98953?

Start tomato seeds indoors around Mar 9 – Mar 23 and set transplants outside around May 11 – May 25, one to three weeks after the median last frost.

How much rain and snow does 98953 get?

About 7.8 inches of precipitation a year and 10 inches of snowfall (NOAA 1991–2020 normals, Moxee City 10 E station).

How hot do summers get in Zillah, WA?

The average high peaks at 88 °F in July, with about 30 days a year at 90 °F or more.

What kind of soil does 98953 have?

The USDA soil survey maps Scoon at the center of ZIP 98953: silt loam, well drained, pH about 7.9 (alkaline).

Did spring come early in Zillah, WA in 2026?

Spring leaf-out near 98953 came on Mar 8 in 2026, 13 days earlier than the 1991–2020 average (Mar 21), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Zillah, WA?

Long-day onions: the longest day near 98953 is 15 h 49 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).