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

Planting zone for 99141 — Kettle Falls, WA

ZIP code 99141 (Kettle Falls, Stevens County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is May 2 and the first fall frost October 2.

Where ZIP 99141 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 2
First frostOct 2
2012 zone6b

Same zone as on the 2012 map. 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 Kettle Falls, 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 Kettle Falls, WA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 2median — 50% chance of a later frost
Safe for tender plantsMay 17only 10% chance of frost after
First fall frostOctober 2median — 10% chance by Sep 19
Growing season153 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 15 and returns around October 14.

From the NOAA station Colville, WA — 15 miles away, elevation 1,555 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 99141

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 21 – Apr 4
SpinachSow outdoors · Mar 21 – Apr 11
Broccoli, cabbageStart indoors · Feb 21 – Mar 7
Broccoli, cabbageTransplant · Apr 11 – Apr 25
Onion setsPlant outdoors · Apr 4 – Apr 18
PotatoesPlant outdoors · Apr 11 – Apr 25
LettuceSow outdoors · Apr 4 – Apr 18
Carrots, beetsSow outdoors · Apr 11 – Apr 25
TomatoesStart indoors · Mar 7 – Mar 21
TomatoesTransplant · May 9 – May 23
Peppers, eggplantStart indoors · Feb 21 – Mar 7
Peppers, eggplantTransplant · May 16 – May 30
BeansSow outdoors · May 9 – May 23
Sweet cornSow outdoors · May 9 – May 23
Cucumbers, squashSow outdoors · May 9 – May 23
Fall lettuce, spinachSow outdoors · Aug 7 – Aug 21
GarlicPlant cloves · Sep 18 – Oct 23
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 2) and first fall frost (Oct 2) 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 99141 came on Apr 9 — 3 days earlier than the 1991–2020 average (Apr 12).

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.

Trees 31

Alaska cedar75 ft · blooms mid spring · low shade tolerance · to −22 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Fbalsam poplar80 ft · blooms late spring · high shade tolerance · to −79 °Fbigleaf maple60 ft · blooms mid spring · medium shade tolerance · to −14 °Fblack locust60 ft · blooms spring · high shade tolerance · to −37 °Fboxelder60 ft · blooms early spring · low shade tolerance · to −46 °F

Shrubs 102

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falpine laurel1 ft · blooms late spring · low shade tolerance · to −28 °FAmerican plum24 ft · blooms mid spring · high shade tolerance · to −38 °Fantelope bitterbrush6 ft · blooms early spring · medium shade tolerance · to −36 °FBarclay's willow15 ft · high shade tolerance · to −43 °F

Wildflowers & perennials 279

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °Falpine mountainsorrel1 ft · blooms mid summer · medium shade tolerance · to −43 °FAmerican alpine speedwell1 ft · blooms summer · medium shade tolerance · to −28 °FAmerican bistort1.5 ft · blooms mid spring · high shade tolerance · to −38 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °F

Grasses 154

Alaska brome5 ft · blooms late spring · low shade tolerance · to −18 °FAlaska oniongrass3 ft · blooms mid spring · low shade tolerance · to −33 °Falkali cordgrass3 ft · blooms late summer · high shade tolerance · to −38 °Falkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °Falpine timothy1.4 ft · blooms late spring · medium shade tolerance · to −43 °FAmerican beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °F

Vines 3

riverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Ftrumpet creeper2 ft · blooms summer · high shade tolerance · to −13 °Fwestern white clematis1 ft · blooms mid summer · medium shade tolerance · to −38 °F

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 Kettle Falls, WA.

Soil in Kettle Falls, WA

The soil mapped at the center of ZIP 99141 is Pepoon — extremely stony ashy loam, well drained.

TextureExtremely stony ashy loama good balance for most vegetables
pH7.2neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2.5%moderate
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Pepoon-Edds complex, 15 to 50 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 99141; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Kettle Falls, WA

Summer high89 °Faverage high, August
Winter low23 °Faverage low, January
Hot days38days a year at 90 °F or more
Freezing nights144nights a year at 32 °F or less
Growing degree days2,357base 50 °F — the season’s usable heat
Longest day16 h 09 mindaylight on June 21
Shortest day8 h 16 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation23.8 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 34 °F, low 23 °F 34°23° JanFebruary: average high 42 °F, low 24 °F 42°24° FebMarch: average high 53 °F, low 30 °F 53°30° MarApril: average high 63 °F, low 35 °F 63°35° AprMay: average high 72 °F, low 43 °F 72°43° MayJune: average high 78 °F, low 49 °F 78°49° JunJuly: average high 88 °F, low 53 °F 88°53° JulAugust: average high 89 °F, low 51 °F 89°51° AugSeptember: average high 78 °F, low 44 °F 78°44° SepOctober: average high 61 °F, low 35 °F 61°35° OctNovember: average high 44 °F, low 29 °F 44°29° NovDecember: average high 34 °F, low 24 °F 34°24° Dec

Precipitation by month inches

0″1″2″3″January: 2.51 in precipitation 2.5 JanFebruary: 1.83 in precipitation 1.8 FebMarch: 2.16 in precipitation 2.2 MarApril: 2.04 in precipitation 2.0 AprMay: 2.40 in precipitation 2.4 MayJune: 2.70 in precipitation 2.7 JunJuly: 1.14 in precipitation 1.1 JulAugust: 0.86 in precipitation 0.9 AugSeptember: 1.30 in precipitation 1.3 SepOctober: 1.55 in precipitation 1.6 OctNovember: 2.44 in precipitation 2.4 NovDecember: 2.90 in precipitation 2.9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Colville, WA (15 mi away); precipitation: Kettle Falls 10.2 Nw, WA (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

991266b
Evans, WA · 9 mi
991606b
Orient, WA · 12 mi
991466b
Laurier, WA · 18 mi
991146a
Colville, WA · 20 mi
991216b
Danville, WA · 20 mi
991506a
Malo, WA · 21 mi
991676b
Rice, WA · 21 mi
991576b
Northport, WA · 22 mi

Washington planting zones →

Questions about 99141

What planting zone is ZIP code 99141?

ZIP code 99141 (Kettle Falls, 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 Kettle Falls, WA?

The median last spring frost (32 °F) near 99141 is May 2; after May 17 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Colville station.

When is the first frost in Kettle Falls, WA?

The median first fall frost near 99141 is October 2, giving a median frost-free growing season of 153 days.

When should I plant tomatoes in 99141?

Start tomato seeds indoors around Mar 7 – Mar 21 and set transplants outside around May 9 – May 23, one to three weeks after the median last frost.

How much rain and snow does 99141 get?

About 23.8 inches of precipitation a year (NOAA 1991–2020 normals, Kettle Falls 10.2 Nw station).

How hot do summers get in Kettle Falls, WA?

The average high peaks at 89 °F in August, with about 38 days a year at 90 °F or more.

What kind of soil does 99141 have?

The USDA soil survey maps Pepoon at the center of ZIP 99141: extremely stony ashy loam, well drained, pH about 7.2 (neutral).

Did spring come early in Kettle Falls, WA in 2026?

Spring leaf-out near 99141 came on Apr 9 in 2026, 3 days earlier than the 1991–2020 average (Apr 12), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Kettle Falls, WA?

Long-day onions: the longest day near 99141 is 16 h 09 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).