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

Planting zone for 97876 — Summerville, OR

ZIP code 97876 (Summerville, Union County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is May 24 and the first fall frost September 18.

Where ZIP 97876 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.

Zone6b−5 to 0 °F
Coldest night−20.6 to −17.8 °C
Last frostMay 24
First frostSep 18
2012 zone6b

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 6b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Summerville, 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 Summerville, OR

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 24median — 50% chance of a later frost
Safe for tender plantsJune 21only 10% chance of frost after
First fall frostSeptember 18median — 10% chance by Sep 1
Growing season114 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 1 and returns around October 1.

From the NOAA station Elgin, OR — 6 miles away, elevation 2,697 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 97876

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 12 – Apr 26
SpinachSow outdoors · Apr 12 – May 3
Broccoli, cabbageStart indoors · Mar 15 – Mar 29
Broccoli, cabbageTransplant · May 3 – May 17
Onion setsPlant outdoors · Apr 26 – May 10
PotatoesPlant outdoors · May 3 – May 17
LettuceSow outdoors · Apr 26 – May 10
Carrots, beetsSow outdoors · May 3 – May 17
TomatoesStart indoors · Mar 29 – Apr 12
TomatoesTransplant · May 31 – Jun 14
Peppers, eggplantStart indoors · Mar 15 – Mar 29
Peppers, eggplantTransplant · Jun 7 – Jun 21
BeansSow outdoors · May 31 – Jun 14
Sweet cornSow outdoors · May 31 – Jun 14
Cucumbers, squashSow outdoors · May 31 – Jun 14
Fall lettuce, spinachSow outdoors · Jul 24 – Aug 7
GarlicPlant cloves · Sep 4 – Oct 9
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 24) and first fall frost (Sep 18) 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 97876 came on Mar 17 — 18 days earlier than the 1991–2020 average (Apr 4).

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 6b in Oregon

613 plants native to the lower 48 states, recorded in Oregon, and rated by the USDA to survive −5 °F or colder — the bottom of zone 6b. 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 114

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 287

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 161

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 Summerville, OR.

Soil in Summerville, OR

The soil mapped at the center of ZIP 97876 is Veazie — loam, well drained.

TextureLoama good balance for most vegetables
pH6.7neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2.5%moderate
Hydrologic groupBwater soaks in moderately
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Veazie-Voats complex.

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 97876; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Summerville, OR

Summer high87 °Faverage high, July
Winter low23 °Faverage low, December
Hot days31days a year at 90 °F or more
Freezing nights164nights a year at 32 °F or less
Growing degree days1,871base 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)
Precipitation25.9 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 40 °F, low 24 °F 40°24° JanFebruary: average high 45 °F, low 25 °F 45°25° FebMarch: average high 53 °F, low 29 °F 53°29° MarApril: average high 60 °F, low 32 °F 60°32° AprMay: average high 69 °F, low 39 °F 69°39° MayJune: average high 76 °F, low 44 °F 76°44° JunJuly: average high 87 °F, low 47 °F 87°47° JulAugust: average high 87 °F, low 46 °F 87°46° AugSeptember: average high 78 °F, low 40 °F 78°40° SepOctober: average high 64 °F, low 32 °F 64°32° OctNovember: average high 48 °F, low 28 °F 48°28° NovDecember: average high 39 °F, low 23 °F 39°23° Dec

Precipitation by month inches

0″1″2″3″4″January: 3.27 in precipitation 3.3 JanFebruary: 2.34 in precipitation 2.3 FebMarch: 2.25 in precipitation 2.3 MarApril: 2.43 in precipitation 2.4 AprMay: 2.39 in precipitation 2.4 MayJune: 1.84 in precipitation 1.8 JunJuly: 0.71 in precipitation 0.7 JulAugust: 0.68 in precipitation 0.7 AugSeptember: 0.96 in precipitation 1.0 SepOctober: 2.16 in precipitation 2.2 OctNovember: 3.15 in precipitation 3.1 NovDecember: 3.77 in precipitation 3.8 Dec

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

Nearby ZIP codes

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

978416b
Imbler, OR · 6 mi
978276b
Elgin, OR · 10 mi
978506b
La Grande, OR · 16 mi
978246b
Cove, OR · 18 mi
978596b
Meacham, OR · 20 mi
978107a
Adams, OR · 21 mi
978867a
Weston, OR · 23 mi
978856b
Wallowa, OR · 27 mi

Oregon planting zones →

Questions about 97876

What planting zone is ZIP code 97876?

ZIP code 97876 (Summerville, OR) is in USDA hardiness zone 6b on the 2023 map: the coldest night of an average winter reaches −5 to 0 °F (−20.6 to −17.8 °C).

When is the last frost in Summerville, OR?

The median last spring frost (32 °F) near 97876 is May 24; after June 21 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Elgin station.

When is the first frost in Summerville, OR?

The median first fall frost near 97876 is September 18, giving a median frost-free growing season of 114 days.

When should I plant tomatoes in 97876?

Start tomato seeds indoors around Mar 29 – Apr 12 and set transplants outside around May 31 – Jun 14, one to three weeks after the median last frost.

How much rain and snow does 97876 get?

About 25.9 inches of precipitation a year (NOAA 1991–2020 normals, Elgin station).

How hot do summers get in Summerville, OR?

The average high peaks at 87 °F in July, with about 31 days a year at 90 °F or more.

What kind of soil does 97876 have?

The USDA soil survey maps Veazie at the center of ZIP 97876: loam, well drained, pH about 6.7 (neutral).

Did spring come early in Summerville, OR in 2026?

Spring leaf-out near 97876 came on Mar 17 in 2026, 18 days earlier than the 1991–2020 average (Apr 4), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Summerville, OR?

Long-day onions: the longest day near 97876 is 15 h 41 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).