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

Planting zone for 97875 — Stanfield, OR

ZIP code 97875 (Stanfield, Umatilla County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 26 and the first fall frost October 10.

Where ZIP 97875 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.

Zone7a0 to 5 °F
Coldest night−17.8 to −15 °C
Last frostApr 26
First frostOct 10
2012 zone7a

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 7a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Stanfield, 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 Stanfield, OR

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 26median — 50% chance of a later frost
Safe for tender plantsMay 10only 10% chance of frost after
First fall frostOctober 10median — 10% chance by Sep 25
Growing season167 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 9 and returns around October 24.

From the NOAA station Hermiston Municipal Airport, OR — 6 miles away, elevation 640 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 97875

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 15 – Mar 29
SpinachSow outdoors · Mar 15 – Apr 5
Broccoli, cabbageStart indoors · Feb 15 – Mar 1
Broccoli, cabbageTransplant · Apr 5 – Apr 19
Onion setsPlant outdoors · Mar 29 – Apr 12
PotatoesPlant outdoors · Apr 5 – Apr 19
LettuceSow outdoors · Mar 29 – Apr 12
Carrots, beetsSow outdoors · Apr 5 – Apr 19
TomatoesStart indoors · Mar 1 – Mar 15
TomatoesTransplant · May 3 – May 17
Peppers, eggplantStart indoors · Feb 15 – Mar 1
Peppers, eggplantTransplant · May 10 – May 24
BeansSow outdoors · May 3 – May 17
Sweet cornSow outdoors · May 3 – May 17
Cucumbers, squashSow outdoors · May 3 – May 17
Fall lettuce, spinachSow outdoors · Aug 15 – Aug 29
GarlicPlant cloves · Sep 26 – Oct 31
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 26) and first fall frost (Oct 10) 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 97875 came on Mar 2 — 7 days earlier than the 1991–2020 average (Mar 9).

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 7a in Oregon

624 plants native to the lower 48 states, recorded in Oregon, and rated by the USDA to survive 0 °F or colder — the bottom of zone 7a. Each links to its USDA PLANTS profile.

Trees 40

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 119

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 290

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 164

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 Stanfield, OR.

Soil in Stanfield, OR

The soil mapped at the center of ZIP 97875 is Adkins — fine sandy loam, well drained.

TextureFine sandy loamdrains and warms fast; dries out and needs more feeding
pH7.2neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter0.85%low — add compost
Hydrologic groupBwater soaks in moderately
Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Adkins fine sandy loam, 0 to 5 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 97875; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Stanfield, OR

Summer high93 °Faverage high, July
Winter low28 °Faverage low, December
Hot days50days a year at 90 °F or more
Freezing nights115nights a year at 32 °F or less
Growing degree days3,173base 50 °F — the season’s usable heat
Longest day15 h 44 mindaylight on June 21
Shortest day8 h 40 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation8.6 inper year, rain and melted snow

Average high and low, by month

20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 43 °F, low 29 °F 43°29° JanFebruary: average high 49 °F, low 29 °F 49°29° FebMarch: average high 59 °F, low 34 °F 59°34° MarApril: average high 67 °F, low 39 °F 67°39° AprMay: average high 76 °F, low 46 °F 76°46° MayJune: average high 82 °F, low 53 °F 82°53° JunJuly: average high 93 °F, low 59 °F 93°59° JulAugust: average high 91 °F, low 57 °F 91°57° AugSeptember: average high 81 °F, low 48 °F 81°48° SepOctober: average high 67 °F, low 39 °F 67°39° OctNovember: average high 51 °F, low 32 °F 51°32° NovDecember: average high 42 °F, low 28 °F 42°28° Dec

Precipitation by month inches

0″1″2″January: 1.14 in precipitation 1.1 JanFebruary: 0.86 in precipitation 0.9 FebMarch: 0.77 in precipitation 0.8 MarApril: 0.78 in precipitation 0.8 AprMay: 0.83 in precipitation 0.8 MayJune: 0.64 in precipitation 0.6 JunJuly: 0.12 in precipitation 0.1 JulAugust: 0.17 in precipitation 0.2 AugSeptember: 0.33 in precipitation 0.3 SepOctober: 0.80 in precipitation 0.8 OctNovember: 1.05 in precipitation 1.1 NovDecember: 1.12 in precipitation 1.1 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Hermiston Municipal Airport, OR (6 mi away); precipitation: Hermiston Municipal Airport, OR (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

978387b
Hermiston, OR · 7 mi
978267a
Echo, OR · 11 mi
978827b
Umatilla, OR · 12 mi
993377b
Kennewick, WA · 17 mi
993467b
Plymouth, WA · 17 mi
978017a
Pendleton, OR · 19 mi
978357a
Helix, OR · 19 mi
993637b
Wallula, WA · 20 mi

Oregon planting zones →

Questions about 97875

What planting zone is ZIP code 97875?

ZIP code 97875 (Stanfield, OR) is in USDA hardiness zone 7a on the 2023 map: the coldest night of an average winter reaches 0 to 5 °F (−17.8 to −15 °C).

When is the last frost in Stanfield, OR?

The median last spring frost (32 °F) near 97875 is April 26; after May 10 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Hermiston Municipal Airport station.

When is the first frost in Stanfield, OR?

The median first fall frost near 97875 is October 10, giving a median frost-free growing season of 167 days.

When should I plant tomatoes in 97875?

Start tomato seeds indoors around Mar 1 – Mar 15 and set transplants outside around May 3 – May 17, one to three weeks after the median last frost.

How much rain and snow does 97875 get?

About 8.6 inches of precipitation a year (NOAA 1991–2020 normals, Hermiston Municipal Airport station).

How hot do summers get in Stanfield, OR?

The average high peaks at 93 °F in July, with about 50 days a year at 90 °F or more.

What kind of soil does 97875 have?

The USDA soil survey maps Adkins at the center of ZIP 97875: fine sandy loam, well drained, pH about 7.2 (neutral).

Did spring come early in Stanfield, OR in 2026?

Spring leaf-out near 97875 came on Mar 2 in 2026, 7 days earlier than the 1991–2020 average (Mar 9), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Stanfield, OR?

Long-day onions: the longest day near 97875 is 15 h 44 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).