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

Planting zone for 98858 — Waterville, WA

ZIP code 98858 (Waterville, Douglas County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is May 14 and the first fall frost October 1.

Where ZIP 98858 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.

Zone6b−5 to 0 °F

Coldest night−20.6 to −17.8 °C

Last frostMay 14

First frostOct 1

2012 zone6a

Was 6a 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 6b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Waterville, 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 Waterville, WA

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 14median — 50% chance of a later frost

Safe for tender plantsJune 4only 10% chance of frost after

First fall frostOctober 1median — 10% chance by Sep 18

Growing season140 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 29 and returns around October 12.

From the NOAA station Waterville, WA — 9 miles away, elevation 2,664 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 98858

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 2 – Apr 16

SpinachSow outdoors · Apr 2 – Apr 23

Broccoli, cabbageStart indoors · Mar 5 – Mar 19

Broccoli, cabbageTransplant · Apr 23 – May 7

Onion setsPlant outdoors · Apr 16 – Apr 30

PotatoesPlant outdoors · Apr 23 – May 7

LettuceSow outdoors · Apr 16 – Apr 30

Carrots, beetsSow outdoors · Apr 23 – May 7

TomatoesStart indoors · Mar 19 – Apr 2

TomatoesTransplant · May 21 – Jun 4

Peppers, eggplantStart indoors · Mar 5 – Mar 19

Peppers, eggplantTransplant · May 28 – Jun 11

BeansSow outdoors · May 21 – Jun 4

Sweet cornSow outdoors · May 21 – Jun 4

Cucumbers, squashSow outdoors · May 21 – Jun 4

Fall lettuce, spinachSow outdoors · Aug 6 – Aug 20

GarlicPlant cloves · Sep 17 – Oct 22

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 14) and first fall frost (Oct 1) 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 98858 came on Apr 1 — 10 days earlier than the 1991–2020 average (Apr 11).

average
Apr 112026
Apr 1

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 6b in Washington

581 plants native to the lower 48 states, recorded in Washington, and rated by the USDA to survive −5 °F or colder — the bottom of zone 6b. 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 Waterville, WA.

Soil in Waterville, WA

The soil mapped at the center of ZIP 98858 is Aarup — ashy fine sandy loam, well drained.

TextureAshy fine sandy loamdrains and warms fast; dries out and needs more feeding

pH6.7neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter1.5%low — add compost

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Aarup ashy fine sandy loam, 0 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 98858; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Waterville, WA

Summer high84 °Faverage high, July

Winter low16 °Faverage low, December

Hot days20days a year at 90 °F or more

Freezing nights161nights a year at 32 °F or less

Growing degree days1,949base 50 °F — the season’s usable heat

Longest day16 h 00 mindaylight on June 21

Shortest day8 h 25 mindaylight on December 21

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

Precipitation11.3 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: Waterville, WA (9 mi away); precipitation: Waterville, WA (9 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.

988177b

Chelan Falls, WA · 9 mi

988437a

Orondo, WA · 10 mi

988457a

Palisades, WA · 17 mi

988027a

East Wenatchee, WA · 18 mi

988507a

Rock Island, WA · 20 mi

988317a

Manson, WA · 21 mi

988306b

Mansfield, WA · 22 mi

988236b

Ephrata, WA · 26 mi

Washington planting zones →

Questions about 98858

What planting zone is ZIP code 98858?

ZIP code 98858 (Waterville, WA) is in USDA hardiness zone 6b on the 2023 map: the coldest night of an average winter reaches −5 to 0 °F (−20.6 to −17.8 °C).

When is the last frost in Waterville, WA?

The median last spring frost (32 °F) near 98858 is May 14; after June 4 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Waterville station.

When is the first frost in Waterville, WA?

The median first fall frost near 98858 is October 1, giving a median frost-free growing season of 140 days.

When should I plant tomatoes in 98858?

Start tomato seeds indoors around Mar 19 – Apr 2 and set transplants outside around May 21 – Jun 4, one to three weeks after the median last frost.

How much rain and snow does 98858 get?

About 11.3 inches of precipitation a year (NOAA 1991–2020 normals, Waterville station).

How hot do summers get in Waterville, WA?

The average high peaks at 84 °F in July, with about 20 days a year at 90 °F or more.

What kind of soil does 98858 have?

The USDA soil survey maps Aarup at the center of ZIP 98858: ashy fine sandy loam, well drained, pH about 6.7 (neutral).

Did spring come early in Waterville, WA in 2026?

Spring leaf-out near 98858 came on Apr 1 in 2026, 10 days earlier than the 1991–2020 average (Apr 11), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Waterville, WA?

Long-day onions: the longest day near 98858 is 16 h 00 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 98858 change?

Yes. The 2012 USDA map put 98858 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.