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

Planting zone for 98940 — Ronald, WA

ZIP code 98940 (Ronald, Kittitas County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is May 9 and the first fall frost October 6.

Where ZIP 98940 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 9

First frostOct 6

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 Ronald, 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 Ronald, WA

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 9median — 50% chance of a later frost

Safe for tender plantsMay 26only 10% chance of frost after

First fall frostOctober 6median — 10% chance by Sep 24

Growing season151 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 24 and returns around October 20.

From the NOAA station Easton, WA — 11 miles away, elevation 2,169 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 98940

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 28 – Apr 11

SpinachSow outdoors · Mar 28 – Apr 18

Broccoli, cabbageStart indoors · Feb 28 – Mar 14

Broccoli, cabbageTransplant · Apr 18 – May 2

Onion setsPlant outdoors · Apr 11 – Apr 25

PotatoesPlant outdoors · Apr 18 – May 2

LettuceSow outdoors · Apr 11 – Apr 25

Carrots, beetsSow outdoors · Apr 18 – May 2

TomatoesStart indoors · Mar 14 – Mar 28

TomatoesTransplant · May 16 – May 30

Peppers, eggplantStart indoors · Feb 28 – Mar 14

Peppers, eggplantTransplant · May 23 – Jun 6

BeansSow outdoors · May 16 – May 30

Sweet cornSow outdoors · May 16 – May 30

Cucumbers, squashSow outdoors · May 16 – May 30

Fall lettuce, spinachSow outdoors · Aug 11 – Aug 25

GarlicPlant cloves · Sep 22 – Oct 27

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 9) and first fall frost (Oct 6) 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 98940 came on Apr 29 — 7 days earlier than the 1991–2020 average (May 6).

average
May 62026
Apr 29

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 Ronald, WA.

Soil in Ronald, WA

The soil mapped at the center of ZIP 98940 is Polallie — 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 groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Polallie-Rock outcrop complex, 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 98940; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Ronald, WA

Summer high76 °Faverage high, July

Winter low25 °Faverage low, January

Hot days7days a year at 90 °F or more

Freezing nights154nights a year at 32 °F or less

Growing degree days1,335base 50 °F — the season’s usable heat

Longest day15 h 57 mindaylight on June 21

Shortest day8 h 27 mindaylight on December 21

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

Precipitation58.6 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: Easton, WA (11 mi away); precipitation: Sasse Ridge, WA (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

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

South Cle Elum, WA · 13 mi

980687a

Snoqualmie Pass, WA · 16 mi

988477a

Peshastin, WA · 20 mi

982888a

Skykomish, WA · 22 mi

989467a

Thorp, WA · 24 mi

Washington planting zones →

Questions about 98940

What planting zone is ZIP code 98940?

ZIP code 98940 (Ronald, 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 Ronald, WA?

The median last spring frost (32 °F) near 98940 is May 9; after May 26 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Easton station.

When is the first frost in Ronald, WA?

The median first fall frost near 98940 is October 6, giving a median frost-free growing season of 151 days.

When should I plant tomatoes in 98940?

Start tomato seeds indoors around Mar 14 – Mar 28 and set transplants outside around May 16 – May 30, one to three weeks after the median last frost.

How much rain and snow does 98940 get?

About 58.6 inches of precipitation a year (NOAA 1991–2020 normals, Sasse Ridge station).

How hot do summers get in Ronald, WA?

The average high peaks at 76 °F in July, with about 7 days a year at 90 °F or more.

What kind of soil does 98940 have?

The USDA soil survey maps Polallie at the center of ZIP 98940: slightly decomposed plant material, well drained, pH about 5.0 (strongly acidic).

Did spring come early in Ronald, WA in 2026?

Spring leaf-out near 98940 came on Apr 29 in 2026, 7 days earlier than the 1991–2020 average (May 6), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Ronald, WA?

Long-day onions: the longest day near 98940 is 15 h 57 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 98940 change?

Yes. The 2012 USDA map put 98940 in zone 6b; the 2023 map puts it in zone 7a. The newer map uses 1991–2020 data and more weather stations.