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

Planting zone for 98922 — Cle Elum, WA

ZIP code 98922 (Cle Elum, Kittitas County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is May 13 and the first fall frost September 25.

Where ZIP 98922 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 13

First frostSep 25

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 Cle Elum, 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 Cle Elum, WA

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 13median — 50% chance of a later frost

Safe for tender plantsJune 1only 10% chance of frost after

First fall frostSeptember 25median — 10% chance by Sep 11

Growing season132 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 28 and returns around October 5.

From the NOAA station Cle Elum, WA — 3 miles away, elevation 1,900 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 98922

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 1 – Apr 15

SpinachSow outdoors · Apr 1 – Apr 22

Broccoli, cabbageStart indoors · Mar 4 – Mar 18

Broccoli, cabbageTransplant · Apr 22 – May 6

Onion setsPlant outdoors · Apr 15 – Apr 29

PotatoesPlant outdoors · Apr 22 – May 6

LettuceSow outdoors · Apr 15 – Apr 29

Carrots, beetsSow outdoors · Apr 22 – May 6

TomatoesStart indoors · Mar 18 – Apr 1

TomatoesTransplant · May 20 – Jun 3

Peppers, eggplantStart indoors · Mar 4 – Mar 18

Peppers, eggplantTransplant · May 27 – Jun 10

BeansSow outdoors · May 20 – Jun 3

Sweet cornSow outdoors · May 20 – Jun 3

Cucumbers, squashSow outdoors · May 20 – Jun 3

Fall lettuce, spinachSow outdoors · Jul 31 – Aug 14

GarlicPlant cloves · Sep 11 – Oct 16

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 13) and first fall frost (Sep 25) 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 98922 came on Apr 7 — 8 days earlier than the 1991–2020 average (Apr 15).

average
Apr 152026
Apr 7

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 Cle Elum, WA.

Soil in Cle Elum, WA

The soil mapped at the center of ZIP 98922 is Nard — slightly decomposed plant material, well drained.

TextureSlightly decomposed plant materialtop layer

pH5.0strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter75%high

Hydrologic groupC/Dslow when drained; wet otherwise

Farmland classFarmland of statewide importanceUSDA classification

Map unit: Nard ashy loam, 5 to 25 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 98922; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Cle Elum, WA

Summer high81 °Faverage high, July

Winter low22 °Faverage low, January

Hot days15days a year at 90 °F or more

Freezing nights156nights a year at 32 °F or less

Growing degree days1,759base 50 °F — the season’s usable heat

Longest day15 h 56 mindaylight on June 21

Shortest day8 h 28 mindaylight on December 21

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

Precipitation24.7 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: Cle Elum, WA (3 mi away); precipitation: Cle Elum, WA (3 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7a.

989437a

South Cle Elum, WA · 6 mi

Peshastin, WA · 18 mi

Washington planting zones →

Questions about 98922

What planting zone is ZIP code 98922?

ZIP code 98922 (Cle Elum, 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 Cle Elum, WA?

The median last spring frost (32 °F) near 98922 is May 13; after June 1 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Cle Elum station.

When is the first frost in Cle Elum, WA?

The median first fall frost near 98922 is September 25, giving a median frost-free growing season of 132 days.

When should I plant tomatoes in 98922?

Start tomato seeds indoors around Mar 18 – Apr 1 and set transplants outside around May 20 – Jun 3, one to three weeks after the median last frost.

How much rain and snow does 98922 get?

About 24.7 inches of precipitation a year (NOAA 1991–2020 normals, Cle Elum station).

How hot do summers get in Cle Elum, WA?

The average high peaks at 81 °F in July, with about 15 days a year at 90 °F or more.

What kind of soil does 98922 have?

The USDA soil survey maps Nard at the center of ZIP 98922: slightly decomposed plant material, well drained, pH about 5.0 (strongly acidic).

Did spring come early in Cle Elum, WA in 2026?

Spring leaf-out near 98922 came on Apr 7 in 2026, 8 days earlier than the 1991–2020 average (Apr 15), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Cle Elum, WA?

Long-day onions: the longest day near 98922 is 15 h 56 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 98922 change?

Yes. The 2012 USDA map put 98922 in zone 6b; the 2023 map puts it in zone 7a. The newer map uses 1991–2020 data and more weather stations.