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

Planting zone for 97146 — Warrenton, OR

ZIP code 97146 (Warrenton, Clatsop County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is March 30 and the first fall frost November 18.

Where ZIP 97146 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.

Zone9a20 to 25 °F
Coldest night−6.7 to −3.9 °C
Last frostMar 30
First frostNov 18
2012 zone9a

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 9a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Warrenton, OR…

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 Warrenton, OR

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMarch 30median — 50% chance of a later frost
Safe for tender plantsApril 28only 10% chance of frost after
First fall frostNovember 18median — 10% chance by Oct 27
Growing season233 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 12 and returns around December 13.

From the NOAA station Ft Clatsop Natl Mem, OR — 2 miles away, elevation 43 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 97146

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 16 – Mar 2
SpinachSow outdoors · Feb 16 – Mar 9
Broccoli, cabbageStart indoors · Jan 19 – Feb 2
Broccoli, cabbageTransplant · Mar 9 – Mar 23
Onion setsPlant outdoors · Mar 2 – Mar 16
PotatoesPlant outdoors · Mar 9 – Mar 23
LettuceSow outdoors · Mar 2 – Mar 16
Carrots, beetsSow outdoors · Mar 9 – Mar 23
TomatoesStart indoors · Feb 2 – Feb 16
TomatoesTransplant · Apr 6 – Apr 20
Peppers, eggplantStart indoors · Jan 19 – Feb 2
Peppers, eggplantTransplant · Apr 13 – Apr 27
BeansSow outdoors · Apr 6 – Apr 20
Sweet cornSow outdoors · Apr 6 – Apr 20
Cucumbers, squashSow outdoors · Apr 6 – Apr 20
Fall lettuce, spinachSow outdoors · Sep 23 – Oct 7
GarlicPlant cloves · Nov 4 – Dec 9
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 30) and first fall frost (Nov 18) 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 97146 came on Feb 3 — 7 days earlier than the 1991–2020 average (Feb 10).

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 9a in Oregon

666 plants native to the lower 48 states, recorded in Oregon, and rated by the USDA to survive 20 °F or colder — the bottom of zone 9a. Each links to its USDA PLANTS profile.

Trees 44

Alaska cedar75 ft · blooms mid spring · low shade tolerance · to −22 °Fbalsam poplar80 ft · blooms late spring · high shade tolerance · to −79 °Fbigleaf maple60 ft · blooms mid spring · medium shade tolerance · to −14 °FBishop pine90 ft · blooms mid spring · low shade tolerance · to 17 °Fblack locust60 ft · blooms spring · high shade tolerance · to −37 °Fboxelder60 ft · blooms early spring · low shade tolerance · to −46 °F

Shrubs 133

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °Falderleaf mountain mahogany15 ft · blooms late spring · medium shade tolerance · to −41 °Falpine laurel1 ft · blooms late spring · low shade tolerance · to −28 °Fantelope bitterbrush6 ft · blooms early spring · medium shade tolerance · to −36 °Fbeaked hazelnut15 ft · blooms early spring · low shade tolerance · to −47 °Fbig sagebrush4 ft · blooms mid summer · high shade tolerance · to −43 °F

Wildflowers & perennials 305

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 169

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 2

riverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °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 Warrenton, OR.

Soil in Warrenton, OR

The soil mapped at the center of ZIP 97146 is Templeton — slightly decomposed plant material, well drained.

TextureSlightly decomposed plant materialtop layer
pH4.5strongly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter75%high
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Templeton-Ecola silt loams, 30 to 60 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 97146; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Warrenton, OR

Summer high71 °Faverage high, August
Winter low37 °Faverage low, February
Hot days1days a year at 90 °F or more
Freezing nights31nights a year at 32 °F or less
Growing degree days1,614base 50 °F — the season’s usable heat
Longest day15 h 46 mindaylight on June 21
Shortest day8 h 37 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation70.3 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°32 °FJanuary: average high 49 °F, low 38 °F 49°38° JanFebruary: average high 51 °F, low 37 °F 51°37° FebMarch: average high 54 °F, low 39 °F 54°39° MarApril: average high 58 °F, low 41 °F 58°41° AprMay: average high 64 °F, low 45 °F 64°45° MayJune: average high 67 °F, low 49 °F 67°49° JunJuly: average high 70 °F, low 53 °F 70°53° JulAugust: average high 71 °F, low 53 °F 71°53° AugSeptember: average high 70 °F, low 49 °F 70°49° SepOctober: average high 61 °F, low 45 °F 61°45° OctNovember: average high 53 °F, low 40 °F 53°40° NovDecember: average high 49 °F, low 37 °F 49°37° Dec

Precipitation by month inches

0″2″4″6″8″10″12″January: 10.59 in precipitation 10.6 JanFebruary: 7.18 in precipitation 7.2 FebMarch: 7.90 in precipitation 7.9 MarApril: 5.80 in precipitation 5.8 AprMay: 3.40 in precipitation 3.4 MayJune: 2.30 in precipitation 2.3 JunJuly: 0.83 in precipitation 0.8 JulAugust: 1.12 in precipitation 1.1 AugSeptember: 2.67 in precipitation 2.7 SepOctober: 6.74 in precipitation 6.7 OctNovember: 11.05 in precipitation 11.1 NovDecember: 10.68 in precipitation 10.7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Ft Clatsop Natl Mem, OR (2 mi away); precipitation: Astoria Regional Airport, OR (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

971219a
Hammond, OR · 6 mi
971038b
Astoria, OR · 10 mi
986148b
Chinook, WA · 11 mi
986249a
Ilwaco, WA · 15 mi
986449a
Seaview, WA · 15 mi
971109a
Cannon Beach, OR · 16 mi
986438b
Rosburg, WA · 17 mi
971388b
Seaside, OR · 18 mi

Oregon planting zones →

Questions about 97146

What planting zone is ZIP code 97146?

ZIP code 97146 (Warrenton, OR) is in USDA hardiness zone 9a on the 2023 map: the coldest night of an average winter reaches 20 to 25 °F (−6.7 to −3.9 °C).

When is the last frost in Warrenton, OR?

The median last spring frost (32 °F) near 97146 is March 30; after April 28 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Ft Clatsop Natl Mem station.

When is the first frost in Warrenton, OR?

The median first fall frost near 97146 is November 18, giving a median frost-free growing season of 233 days.

When should I plant tomatoes in 97146?

Start tomato seeds indoors around Feb 2 – Feb 16 and set transplants outside around Apr 6 – Apr 20, one to three weeks after the median last frost.

How much rain and snow does 97146 get?

About 70.3 inches of precipitation a year (NOAA 1991–2020 normals, Astoria Regional Airport station).

How hot do summers get in Warrenton, OR?

The average high peaks at 71 °F in August, with about 1 days a year at 90 °F or more.

What kind of soil does 97146 have?

The USDA soil survey maps Templeton at the center of ZIP 97146: slightly decomposed plant material, well drained, pH about 4.5 (strongly acidic).

Did spring come early in Warrenton, OR in 2026?

Spring leaf-out near 97146 came on Feb 3 in 2026, 7 days earlier than the 1991–2020 average (Feb 10), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Warrenton, OR?

Long-day onions: the longest day near 97146 is 15 h 46 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).