Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for Portland, OR

Portland, OR is in USDA zones 8b to 9a across its 59 ZIP codes. The median last spring frost is February 25 and the first fall frost December 1.

Portland on the zone map

Outlined: its 34 ZIP code areas · 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.

Zones8b–9a15 to 25 °F

ZIP codes59

Last frostFeb 25

First frostDec 1

Growing season280 days

8b 15 ZIPs 9a 44 ZIPs

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 frostFebruary 25median — 50% chance of a later frost

Safe for tender plantsMarch 21only 10% chance of frost after

First fall frostDecember 1median — 10% chance by Nov 10

Growing season280 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 31 and returns around December 20.

From the NOAA station Portland Kgw-Tv, OR, elevation 161 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 Portland

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Jan 14 – Jan 28

SpinachSow outdoors · Jan 14 – Feb 4

Broccoli, cabbageStart indoors · Dec 17 – Dec 31

Broccoli, cabbageTransplant · Feb 4 – Feb 18

Onion setsPlant outdoors · Jan 28 – Feb 11

PotatoesPlant outdoors · Feb 4 – Feb 18

LettuceSow outdoors · Jan 28 – Feb 11

Carrots, beetsSow outdoors · Feb 4 – Feb 18

TomatoesStart indoors · Dec 31 – Jan 14

TomatoesTransplant · Mar 4 – Mar 18

Peppers, eggplantStart indoors · Dec 17 – Dec 31

Peppers, eggplantTransplant · Mar 11 – Mar 25

BeansSow outdoors · Mar 4 – Mar 18

Sweet cornSow outdoors · Mar 4 – Mar 18

Cucumbers, squashSow outdoors · Mar 4 – Mar 18

Fall lettuce, spinachSow outdoors · Oct 6 – Oct 20

GarlicPlant cloves · Nov 17 – Dec 22

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 25) and first fall frost (Dec 1) 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 97204 came on Feb 7 — 9 days earlier than the 1991–2020 average (Feb 16).

average
Feb 162026
Feb 7

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).

Soil in Portland, OR

The center of ZIP 97204 is mapped as Urban land, 0 to 3 percent slopes: built-over ground without natural soil data. Garden soil here is usually imported or disturbed — test before you plant.

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 97204; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Portland, OR

Summer high81 °Faverage high, August

Winter low37 °Faverage low, January

Hot days11days a year at 90 °F or more

Freezing nights18nights a year at 32 °F or less

Growing degree days2,697base 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)

Precipitation44.1 inper year, rain and melted snow

Snowfall4 inper year; 2 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Portland Kgw-Tv, OR (within 1 mile); precipitation: Portland Kgw-Tv, OR (within 1 mile). Daylight is calculated from latitude.