Planting zone for 99140 — Keller, WA
ZIP code 99140 (Keller, Ferry County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 22 and the first fall frost October 21.
Where ZIP 99140 is
Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoomNot 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.
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 ServiceLoading the forecast for Keller, 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 Keller, WA
A hard freeze (28 °F) usually ends around April 1 and returns around November 1.
From the NOAA station Coulee Dam 1 Sw, WA — 20 miles away, elevation 1,719 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 99140
Counted from the median last spring frost (Apr 22) and first fall frost (Oct 21) 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 99140 came on Apr 1 — 8 days earlier than the 1991–2020 average (Apr 9).
Apr 92026
Apr 1
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
Shrubs 105
Wildflowers & perennials 282
Grasses 157
Vines 3
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 Keller, WA.
Soil in Keller, WA
The soil mapped at the center of ZIP 99140 is Northstar — gravelly ashy loam, well drained.
Map unit: Northstar-Johntom-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 99140; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.
Climate in Keller, WA
Average high and low, by month
Precipitation by month inches
NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Coulee Dam 1 Sw, WA (20 mi away); precipitation: Gold Mountain, WA (10 mi away). Daylight is calculated from latitude.
Nearby ZIP codes
3 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.
Questions about 99140
What planting zone is ZIP code 99140?
ZIP code 99140 (Keller, 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 Keller, WA?
The median last spring frost (32 °F) near 99140 is April 22; after May 7 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Coulee Dam 1 Sw station.
When is the first frost in Keller, WA?
The median first fall frost near 99140 is October 21, giving a median frost-free growing season of 180 days.
When should I plant tomatoes in 99140?
Start tomato seeds indoors around Feb 25 – Mar 11 and set transplants outside around Apr 29 – May 13, one to three weeks after the median last frost.
How much rain and snow does 99140 get?
About 22.9 inches of precipitation a year (NOAA 1991–2020 normals, Gold Mountain station).
How hot do summers get in Keller, WA?
The average high peaks at 88 °F in July, with about 33 days a year at 90 °F or more.
What kind of soil does 99140 have?
The USDA soil survey maps Northstar at the center of ZIP 99140: gravelly ashy loam, well drained, pH about 6.1 (slightly acidic).
Did spring come early in Keller, WA in 2026?
Spring leaf-out near 99140 came on Apr 1 in 2026, 8 days earlier than the 1991–2020 average (Apr 9), according to the USA National Phenology Network Spring Index.
What kind of onions grow in Keller, WA?
Long-day onions: the longest day near 99140 is 16 h 04 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).
Did the zone for 99140 change?
Yes. The 2012 USDA map put 99140 in zone 6b; the 2023 map puts it in zone 7a. The newer map uses 1991–2020 data and more weather stations.