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

Planting zone for 99122 — Davenport, WA

ZIP code 99122 (Davenport, Lincoln County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is June 6 and the first fall frost September 11.

Where ZIP 99122 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 frostJun 6
First frostSep 11
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 Davenport, 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 Davenport, WA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostJune 6median — 50% chance of a later frost
Safe for tender plantsJuly 5only 10% chance of frost after
First fall frostSeptember 11median — 10% chance by Aug 26
Growing season94 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 11 and returns around September 27.

From the NOAA station Davenport, WA — 3 miles away, elevation 2,369 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 99122

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 25 – May 9
SpinachSow outdoors · Apr 25 – May 16
Broccoli, cabbageStart indoors · Mar 28 – Apr 11
Broccoli, cabbageTransplant · May 16 – May 30
Onion setsPlant outdoors · May 9 – May 23
PotatoesPlant outdoors · May 16 – May 30
LettuceSow outdoors · May 9 – May 23
Carrots, beetsSow outdoors · May 16 – May 30
TomatoesStart indoors · Apr 11 – Apr 25
TomatoesTransplant · Jun 13 – Jun 27
Peppers, eggplantStart indoors · Mar 28 – Apr 11
Peppers, eggplantTransplant · Jun 20 – Jul 4
BeansSow outdoors · Jun 13 – Jun 27
Sweet cornSow outdoors · Jun 13 – Jun 27
Cucumbers, squashSow outdoors · Jun 13 – Jun 27
Fall lettuce, spinachSow outdoors · Jul 17 – Jul 31
GarlicPlant cloves · Aug 28 – Oct 2
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 6) and first fall frost (Sep 11) 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 99122 came on Apr 1 — 10 days earlier than the 1991–2020 average (Apr 11).

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 Davenport, WA.

Soil in Davenport, WA

The soil mapped at the center of ZIP 99122 is Tucannon — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH6.7neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2.5%moderate
Hydrologic groupCwater soaks in slowly
Farmland classprime farmlandUSDA classification

Map unit: Tucannon silt loam, 0 to 5 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 99122; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Davenport, WA

Summer high83 °Faverage high, August
Winter low19 °Faverage low, January
Hot days18days a year at 90 °F or more
Freezing nights175nights a year at 32 °F or less
Growing degree days1,574base 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)
Precipitation14 inper year, rain and melted snow
Snowfall30 inper year; 48 days with snow on the ground

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 32 °F, low 19 °F 32°19° JanFebruary: average high 37 °F, low 21 °F 37°21° FebMarch: average high 47 °F, low 27 °F 47°27° MarApril: average high 56 °F, low 31 °F 56°31° AprMay: average high 65 °F, low 39 °F 65°39° MayJune: average high 72 °F, low 43 °F 72°43° JunJuly: average high 82 °F, low 48 °F 82°48° JulAugust: average high 83 °F, low 48 °F 83°48° AugSeptember: average high 73 °F, low 40 °F 73°40° SepOctober: average high 57 °F, low 31 °F 57°31° OctNovember: average high 42 °F, low 25 °F 42°25° NovDecember: average high 31 °F, low 19 °F 31°19° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″January: 1.73 in precipitation, 7.4 in snowfall 1.7❄7 JanFebruary: 0.99 in precipitation, 5.5 in snowfall 1.0❄6 FebMarch: 1.53 in precipitation, 2.2 in snowfall 1.5❄2 MarApril: 1.11 in precipitation, 0.2 in snowfall 1.1 AprMay: 1.37 in precipitation 1.4 MayJune: 1.15 in precipitation 1.1 JunJuly: 0.42 in precipitation 0.4 JulAugust: 0.30 in precipitation 0.3 AugSeptember: 0.49 in precipitation 0.5 SepOctober: 1.26 in precipitation, 0.3 in snowfall 1.3 OctNovember: 1.72 in precipitation, 4.1 in snowfall 1.7❄4 NovDecember: 1.90 in precipitation, 10.6 in snowfall 1.9❄11 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Davenport, WA (3 mi away); precipitation: Davenport, WA (3 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.

991477a
Lincoln, WA · 17 mi
991346b
Harrington, WA · 17 mi
990407a
Wellpinit, WA · 17 mi
990296b
Reardan, WA · 18 mi
990086b
Edwall, WA · 18 mi
991546b
Mohler, WA · 22 mi
990136b
Ford, WA · 22 mi
990346b
Tumtum, WA · 25 mi

Washington planting zones →

Questions about 99122

What planting zone is ZIP code 99122?

ZIP code 99122 (Davenport, 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 Davenport, WA?

The median last spring frost (32 °F) near 99122 is June 6; after July 5 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Davenport station.

When is the first frost in Davenport, WA?

The median first fall frost near 99122 is September 11, giving a median frost-free growing season of 94 days.

When should I plant tomatoes in 99122?

Start tomato seeds indoors around Apr 11 – Apr 25 and set transplants outside around Jun 13 – Jun 27, one to three weeks after the median last frost.

How much rain and snow does 99122 get?

About 14 inches of precipitation a year and 30 inches of snowfall (NOAA 1991–2020 normals, Davenport station).

How hot do summers get in Davenport, WA?

The average high peaks at 83 °F in August, with about 18 days a year at 90 °F or more.

What kind of soil does 99122 have?

The USDA soil survey maps Tucannon at the center of ZIP 99122: silt loam, well drained, pH about 6.7 (neutral).

Did spring come early in Davenport, WA in 2026?

Spring leaf-out near 99122 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 Davenport, WA?

Long-day onions: the longest day near 99122 is 16 h 00 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 99122 change?

Yes. The 2012 USDA map put 99122 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.