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

Planting zone for 97338 — Dallas, OR

ZIP code 97338 (Dallas, Polk 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 November 1.

Where ZIP 97338 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 frostNov 1
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 Dallas, 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 Dallas, 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 frostNovember 1median — 10% chance by Oct 13
Growing season199 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 7 and returns around November 20.

From the NOAA station Dallas 2 Ne, OR — 2 miles away, elevation 289 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 97338

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 · Sep 6 – Sep 20
GarlicPlant cloves · Oct 18 – Nov 22
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 16) and first fall frost (Nov 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 97338 came on Feb 23 — about the same time as the 1991–2020 average (Feb 21).

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 Dallas, OR.

Soil in Dallas, OR

The soil mapped at the center of ZIP 97338 is Rickreall — silty clay loam, well drained.

TextureSilty clay loamholds water and nutrients; slow to drain and warm up
pH5.3strongly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter6.5%high
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Rickreall silty clay loam, 3 to 12 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 97338; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Dallas, OR

Summer high83 °Faverage high, July
Winter low35 °Faverage low, January
Hot days17days a year at 90 °F or more
Freezing nights49nights a year at 32 °F or less
Growing degree days2,317base 50 °F — the season’s usable heat
Longest day15 h 37 mindaylight on June 21
Shortest day8 h 46 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation49.4 inper year, rain and melted snow

Average high and low, by month

20°30°40°50°60°70°80°90°32 °FJanuary: average high 47 °F, low 35 °F 47°35° JanFebruary: average high 51 °F, low 36 °F 51°36° FebMarch: average high 56 °F, low 38 °F 56°38° MarApril: average high 61 °F, low 40 °F 61°40° AprMay: average high 68 °F, low 45 °F 68°45° MayJune: average high 73 °F, low 49 °F 73°49° JunJuly: average high 83 °F, low 52 °F 83°52° JulAugust: average high 83 °F, low 52 °F 83°52° AugSeptember: average high 78 °F, low 49 °F 78°49° SepOctober: average high 65 °F, low 44 °F 65°44° OctNovember: average high 52 °F, low 38 °F 52°38° NovDecember: average high 46 °F, low 35 °F 46°35° Dec

Precipitation by month inches

0″2″4″6″8″10″January: 7.74 in precipitation 7.7 JanFebruary: 5.66 in precipitation 5.7 FebMarch: 5.74 in precipitation 5.7 MarApril: 4.05 in precipitation 4.0 AprMay: 2.52 in precipitation 2.5 MayJune: 1.55 in precipitation 1.6 JunJuly: 0.33 in precipitation 0.3 JulAugust: 0.40 in precipitation 0.4 AugSeptember: 1.72 in precipitation 1.7 SepOctober: 3.87 in precipitation 3.9 OctNovember: 6.46 in precipitation 6.5 NovDecember: 9.36 in precipitation 9.4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Dallas 2 Ne, OR (2 mi away); precipitation: Dallas 0.3 Ne, OR (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 8b.

973448b
Falls City, OR · 8 mi
973718b
Rickreall, OR · 8 mi
973618b
Monmouth, OR · 11 mi
973788b
Sheridan, OR · 11 mi
971018b
Amity, OR · 12 mi
973048b
Salem, OR · 12 mi
973518b
Independence, OR · 13 mi
973068b
Salem, OR · 14 mi

Oregon planting zones →

Questions about 97338

What planting zone is ZIP code 97338?

ZIP code 97338 (Dallas, 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 Dallas, OR?

The median last spring frost (32 °F) near 97338 is April 16; after May 5 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Dallas 2 Ne station.

When is the first frost in Dallas, OR?

The median first fall frost near 97338 is November 1, giving a median frost-free growing season of 199 days.

When should I plant tomatoes in 97338?

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 97338 get?

About 49.4 inches of precipitation a year (NOAA 1991–2020 normals, Dallas 0.3 Ne station).

How hot do summers get in Dallas, OR?

The average high peaks at 83 °F in July, with about 17 days a year at 90 °F or more.

What kind of soil does 97338 have?

The USDA soil survey maps Rickreall at the center of ZIP 97338: silty clay loam, well drained, pH about 5.3 (strongly acidic).

Did spring come early in Dallas, OR in 2026?

Spring leaf-out near 97338 came on Feb 23 in 2026, about the same as the 1991–2020 average (Feb 21), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Dallas, OR?

Long-day onions: the longest day near 97338 is 15 h 37 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).