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

Planting zone for 97113 — Cornelius, OR

ZIP code 97113 (Cornelius, Washington County) is in USDA zone 8b: the coldest winter night averages 15 to 20 °F. The median last spring frost is April 16 and the first fall frost October 26.

Where ZIP 97113 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.

Zone8b15 to 20 °F
Coldest night−9.4 to −6.7 °C
Last frostApr 16
First frostOct 26
2012 zone8b

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 8b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Cornelius, 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 Cornelius, OR

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 16median — 50% chance of a later frost
Safe for tender plantsMay 5only 10% chance of frost after
First fall frostOctober 26median — 10% chance by Oct 6
Growing season192 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 19 and returns around November 11.

From the NOAA station Forest Grove, OR — 3 miles away, elevation 180 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 97113

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 5 – Mar 19
SpinachSow outdoors · Mar 5 – Mar 26
Broccoli, cabbageStart indoors · Feb 5 – Feb 19
Broccoli, cabbageTransplant · Mar 26 – Apr 9
Onion setsPlant outdoors · Mar 19 – Apr 2
PotatoesPlant outdoors · Mar 26 – Apr 9
LettuceSow outdoors · Mar 19 – Apr 2
Carrots, beetsSow outdoors · Mar 26 – Apr 9
TomatoesStart indoors · Feb 19 – Mar 5
TomatoesTransplant · Apr 23 – May 7
Peppers, eggplantStart indoors · Feb 5 – Feb 19
Peppers, eggplantTransplant · Apr 30 – May 14
BeansSow outdoors · Apr 23 – May 7
Sweet cornSow outdoors · Apr 23 – May 7
Cucumbers, squashSow outdoors · Apr 23 – May 7
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 16) 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 97113 came on Feb 20 — about the same time as the 1991–2020 average (Feb 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 8b in Oregon

661 plants native to the lower 48 states, recorded in Oregon, and rated by the USDA to survive 15 °F or colder — the bottom of zone 8b. Each links to its USDA PLANTS profile.

Trees 43

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 °Fblack locust60 ft · blooms spring · high shade tolerance · to −37 °Fboxelder60 ft · blooms early spring · low shade tolerance · to −46 °FBrewer spruce100 ft · blooms early summer · low shade tolerance · to −13 °F

Shrubs 132

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 166

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 Cornelius, OR.

Soil in Cornelius, OR

The soil mapped at the center of ZIP 97113 is Chehalis — silty clay loam, well drained.

TextureSilty clay loamholds water and nutrients; slow to drain and warm up
pH6.1slightly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter7.5%high
Hydrologic groupBwater soaks in moderately
Farmland classprime farmlandUSDA classification

Map unit: Chehalis silty clay loam, occasional overflow.

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 97113; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Cornelius, OR

Summer high82 °Faverage high, August
Winter low33 °Faverage low, January
Hot days23days a year at 90 °F or more
Freezing nights61nights a year at 32 °F or less
Growing degree days2,256base 50 °F — the season’s usable heat
Longest day15 h 41 mindaylight on June 21
Shortest day8 h 42 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation46.7 inper year, rain and melted snow
Snowfall3 inper year; 1 days with snow on the ground

Average high and low, by month

20°30°40°50°60°70°80°90°32 °FJanuary: average high 45 °F, low 33 °F 45°33° JanFebruary: average high 49 °F, low 33 °F 49°33° FebMarch: average high 55 °F, low 36 °F 55°36° MarApril: average high 60 °F, low 39 °F 60°39° AprMay: average high 68 °F, low 45 °F 68°45° MayJune: average high 73 °F, low 50 °F 73°50° JunJuly: average high 81 °F, low 54 °F 81°54° JulAugust: average high 82 °F, low 54 °F 82°54° AugSeptember: average high 76 °F, low 49 °F 76°49° SepOctober: average high 63 °F, low 42 °F 63°42° OctNovember: average high 51 °F, low 36 °F 51°36° NovDecember: average high 44 °F, low 33 °F 44°33° Dec

Precipitation by month inches · ❄ = snowfall

0″2″4″6″8″January: 7.19 in precipitation, 0.6 in snowfall 7.2❄1 JanFebruary: 5.76 in precipitation, 0.6 in snowfall 5.8❄1 FebMarch: 5.03 in precipitation 5.0 MarApril: 3.33 in precipitation 3.3 AprMay: 2.19 in precipitation 2.2 MayJune: 1.40 in precipitation 1.4 JunJuly: 0.32 in precipitation 0.3 JulAugust: 0.51 in precipitation 0.5 AugSeptember: 1.34 in precipitation 1.3 SepOctober: 3.70 in precipitation, 0.2 in snowfall 3.7 OctNovember: 7.23 in precipitation 7.2 NovDecember: 8.72 in precipitation, 1.3 in snowfall 8.7❄1 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Forest Grove, OR (3 mi away); precipitation: Forest Grove, OR (3 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

971298b
Hillsboro, OR · 4 mi
971238b
Hillsboro, OR · 5 mi
971248b
Hillsboro, OR · 6 mi
970788b
Beaverton, OR · 8 mi
971168b
Forest Grove, OR · 8 mi
970039a
Beaverton, OR · 9 mi
971198b
Gaston, OR · 9 mi
970068b
Beaverton, OR · 9 mi

Oregon planting zones →

Questions about 97113

What planting zone is ZIP code 97113?

ZIP code 97113 (Cornelius, OR) is in USDA hardiness zone 8b on the 2023 map: the coldest night of an average winter reaches 15 to 20 °F (−9.4 to −6.7 °C).

When is the last frost in Cornelius, OR?

The median last spring frost (32 °F) near 97113 is April 16; after May 5 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Forest Grove station.

When is the first frost in Cornelius, OR?

The median first fall frost near 97113 is October 26, giving a median frost-free growing season of 192 days.

When should I plant tomatoes in 97113?

Start tomato seeds indoors around Feb 19 – Mar 5 and set transplants outside around Apr 23 – May 7, one to three weeks after the median last frost.

How much rain and snow does 97113 get?

About 46.7 inches of precipitation a year and 3 inches of snowfall (NOAA 1991–2020 normals, Forest Grove station).

How hot do summers get in Cornelius, OR?

The average high peaks at 82 °F in August, with about 23 days a year at 90 °F or more.

What kind of soil does 97113 have?

The USDA soil survey maps Chehalis at the center of ZIP 97113: silty clay loam, well drained, pH about 6.1 (slightly acidic).

Did spring come early in Cornelius, OR in 2026?

Spring leaf-out near 97113 came on Feb 20 in 2026, about the same as the 1991–2020 average (Feb 20), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Cornelius, OR?

Long-day onions: the longest day near 97113 is 15 h 41 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).