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

Planting zone for 99401 — Anatone, WA

ZIP code 99401 (Anatone, Asotin County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 6 and the first fall frost October 26.

Where ZIP 99401 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 6

First frostOct 26

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 Anatone, 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 Anatone, WA

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 6median — 50% chance of a later frost

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

First fall frostOctober 26median — 10% chance by Oct 10

Growing season200 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 15 and returns around November 8.

From the NOAA station Lewiston Nez Perce Co. Airport, ID — 23 miles away, elevation 1,437 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 99401

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 23 – Mar 9

SpinachSow outdoors · Feb 23 – Mar 16

Broccoli, cabbageStart indoors · Jan 26 – Feb 9

Broccoli, cabbageTransplant · Mar 16 – Mar 30

Onion setsPlant outdoors · Mar 9 – Mar 23

PotatoesPlant outdoors · Mar 16 – Mar 30

LettuceSow outdoors · Mar 9 – Mar 23

Carrots, beetsSow outdoors · Mar 16 – Mar 30

TomatoesStart indoors · Feb 9 – Feb 23

TomatoesTransplant · Apr 13 – Apr 27

Peppers, eggplantStart indoors · Jan 26 – Feb 9

Peppers, eggplantTransplant · Apr 20 – May 4

BeansSow outdoors · Apr 13 – Apr 27

Sweet cornSow outdoors · Apr 13 – Apr 27

Cucumbers, squashSow outdoors · Apr 13 – Apr 27

Fall lettuce, spinachSow outdoors · Aug 31 – Sep 14

GarlicPlant cloves · Oct 12 – Nov 16

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 6) and first fall frost (Oct 26) 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 99401 came on Mar 20 — 16 days earlier than the 1991–2020 average (Apr 5).

average
Apr 52026
Mar 20

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 Anatone, WA.

Soil in Anatone, WA

The soil mapped at the center of ZIP 99401 is Larabee — 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 groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Larabee-Getaway-Anatone complex, 60 to 90 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 99401; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Anatone, WA

Summer high91 °Faverage high, July

Winter low30 °Faverage low, January

Hot days44days a year at 90 °F or more

Freezing nights80nights a year at 32 °F or less

Growing degree days3,143base 50 °F — the season’s usable heat

Longest day15 h 46 mindaylight on June 21

Shortest day8 h 38 mindaylight on December 21

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

Precipitation15.2 inper year, rain and melted snow

Snowfall11 inper year

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Lewiston Nez Perce Co. Airport, ID (23 mi away); precipitation: Asotin 14 Sw, WA (8 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

Clarkston, WA · 20 mi

835556b

Winchester, ID · 26 mi

Uniontown, WA · 29 mi

978856b

Wallowa, OR · 33 mi

Washington planting zones →

Questions about 99401

What planting zone is ZIP code 99401?

ZIP code 99401 (Anatone, 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 Anatone, WA?

The median last spring frost (32 °F) near 99401 is April 6; after April 26 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Lewiston Nez Perce Co. Airport station.

When is the first frost in Anatone, WA?

The median first fall frost near 99401 is October 26, giving a median frost-free growing season of 200 days.

When should I plant tomatoes in 99401?

Start tomato seeds indoors around Feb 9 – Feb 23 and set transplants outside around Apr 13 – Apr 27, one to three weeks after the median last frost.

How much rain and snow does 99401 get?

About 15.2 inches of precipitation a year and 11 inches of snowfall (NOAA 1991–2020 normals, Asotin 14 Sw station).

How hot do summers get in Anatone, WA?

The average high peaks at 91 °F in July, with about 44 days a year at 90 °F or more.

What kind of soil does 99401 have?

The USDA soil survey maps Larabee at the center of ZIP 99401: slightly decomposed plant material, well drained, pH about 5.0 (strongly acidic).

Did spring come early in Anatone, WA in 2026?

Spring leaf-out near 99401 came on Mar 20 in 2026, 16 days earlier than the 1991–2020 average (Apr 5), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Anatone, WA?

Long-day onions: the longest day near 99401 is 15 h 46 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 99401 change?

Yes. The 2012 USDA map put 99401 in zone 6b; the 2023 map puts it in zone 7a. The newer map uses 1991–2020 data and more weather stations.