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

Planting zone for 97223 — Portland, OR

ZIP code 97223 (Portland, Washington County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is April 1 and the first fall frost November 6.

Where ZIP 97223 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 frostApr 1
First frostNov 6
2012 zone8b

Was 8b 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 9a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Portland, 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 Portland, OR

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 1median — 50% chance of a later frost
Safe for tender plantsApril 26only 10% chance of frost after
First fall frostNovember 6median — 10% chance by Oct 19
Growing season222 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 26 and returns around November 30.

From the NOAA station Beaverton 2 Ssw, OR — 2 miles away, elevation 269 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 97223

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 18 – Mar 4
SpinachSow outdoors · Feb 18 – Mar 11
Broccoli, cabbageStart indoors · Jan 21 – Feb 4
Broccoli, cabbageTransplant · Mar 11 – Mar 25
Onion setsPlant outdoors · Mar 4 – Mar 18
PotatoesPlant outdoors · Mar 11 – Mar 25
LettuceSow outdoors · Mar 4 – Mar 18
Carrots, beetsSow outdoors · Mar 11 – Mar 25
TomatoesStart indoors · Feb 4 – Feb 18
TomatoesTransplant · Apr 8 – Apr 22
Peppers, eggplantStart indoors · Jan 21 – Feb 4
Peppers, eggplantTransplant · Apr 15 – Apr 29
BeansSow outdoors · Apr 8 – Apr 22
Sweet cornSow outdoors · Apr 8 – Apr 22
Cucumbers, squashSow outdoors · Apr 8 – Apr 22
Fall lettuce, spinachSow outdoors · Sep 11 – Sep 25
GarlicPlant cloves · Oct 23 – Nov 27
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 1) and first fall frost (Nov 6) 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 97223 came on Feb 8 — 7 days earlier than the 1991–2020 average (Feb 15).

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 Portland, OR.

Soil in Portland, OR

The soil mapped at the center of ZIP 97223 is Aloha — silt loam, somewhat poorly drained.

TextureSilt loama good balance for most vegetables
pH5.8moderately acidic; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter2.5%moderate
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classPrime farmland if drainedUSDA classification

Map unit: Aloha silt loam.

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 97223; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Portland, OR

Summer high82 °Faverage high, July
Winter low34 °Faverage low, January
Hot days15days a year at 90 °F or more
Freezing nights42nights a year at 32 °F or less
Growing degree days2,459base 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)
Precipitation42 inper year, rain and melted snow

Average high and low, by month

20°30°40°50°60°70°80°90°32 °FJanuary: average high 49 °F, low 34 °F 49°34° JanFebruary: average high 53 °F, low 35 °F 53°35° FebMarch: average high 58 °F, low 37 °F 58°37° MarApril: average high 64 °F, low 40 °F 64°40° AprMay: average high 70 °F, low 46 °F 70°46° MayJune: average high 75 °F, low 50 °F 75°50° JunJuly: average high 82 °F, low 54 °F 82°54° JulAugust: average high 82 °F, low 54 °F 82°54° AugSeptember: average high 77 °F, low 50 °F 77°50° SepOctober: average high 65 °F, low 43 °F 65°43° OctNovember: average high 54 °F, low 38 °F 54°38° NovDecember: average high 48 °F, low 34 °F 48°34° Dec

Precipitation by month inches

0″2″4″6″8″January: 6.06 in precipitation 6.1 JanFebruary: 4.49 in precipitation 4.5 FebMarch: 4.33 in precipitation 4.3 MarApril: 3.35 in precipitation 3.4 AprMay: 2.51 in precipitation 2.5 MayJune: 1.55 in precipitation 1.6 JunJuly: 0.46 in precipitation 0.5 JulAugust: 0.54 in precipitation 0.5 AugSeptember: 1.49 in precipitation 1.5 SepOctober: 3.72 in precipitation 3.7 OctNovember: 6.21 in precipitation 6.2 NovDecember: 7.34 in precipitation 7.3 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Beaverton 2 Ssw, OR (2 mi away); precipitation: Beaverton 0.7 Sse, OR (2 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.

970799a
Beaverton, OR · 1 mi
970089a
Beaverton, OR · 2 mi
972249a
Portland, OR · 3 mi
970359a
Lake Oswego, OR · 3 mi
970759a
Beaverton, OR · 3 mi
970768b
Beaverton, OR · 3 mi
970779a
Beaverton, OR · 3 mi
970059a
Beaverton, OR · 4 mi

All 59 ZIP codes in Portland → · Oregon planting zones →

Questions about 97223

What planting zone is ZIP code 97223?

ZIP code 97223 (Portland, 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 Portland, OR?

The median last spring frost (32 °F) near 97223 is April 1; after April 26 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Beaverton 2 Ssw station.

When is the first frost in Portland, OR?

The median first fall frost near 97223 is November 6, giving a median frost-free growing season of 222 days.

When should I plant tomatoes in 97223?

Start tomato seeds indoors around Feb 4 – Feb 18 and set transplants outside around Apr 8 – Apr 22, one to three weeks after the median last frost.

How much rain and snow does 97223 get?

About 42 inches of precipitation a year (NOAA 1991–2020 normals, Beaverton 0.7 Sse station).

How hot do summers get in Portland, OR?

The average high peaks at 82 °F in July, with about 15 days a year at 90 °F or more.

What kind of soil does 97223 have?

The USDA soil survey maps Aloha at the center of ZIP 97223: silt loam, somewhat poorly drained, pH about 5.8 (moderately acidic).

Did spring come early in Portland, OR in 2026?

Spring leaf-out near 97223 came on Feb 8 in 2026, 7 days earlier than the 1991–2020 average (Feb 15), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Portland, OR?

Long-day onions: the longest day near 97223 is 15 h 41 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 97223 change?

Yes. The 2012 USDA map put 97223 in zone 8b; the 2023 map puts it in zone 9a. The newer map uses 1991–2020 data and more weather stations.