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

Planting zone for 97534 — O Brien, OR

ZIP code 97534 (O Brien, Josephine County) is in USDA zone 8b: the coldest winter night averages 15 to 20 °F. The median last spring frost is May 1 and the first fall frost October 12.

Where ZIP 97534 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 frostMay 1
First frostOct 12
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 O Brien, 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 O Brien, OR

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 1median — 50% chance of a later frost
Safe for tender plantsMay 23only 10% chance of frost after
First fall frostOctober 12median — 10% chance by Sep 23
Growing season161 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 4 and returns around November 2.

From the NOAA station Cave Junction 1 Wnw, OR — 10 miles away, elevation 1,378 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 97534

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 20 – Apr 3
SpinachSow outdoors · Mar 20 – Apr 10
Broccoli, cabbageStart indoors · Feb 20 – Mar 6
Broccoli, cabbageTransplant · Apr 10 – Apr 24
Onion setsPlant outdoors · Apr 3 – Apr 17
PotatoesPlant outdoors · Apr 10 – Apr 24
LettuceSow outdoors · Apr 3 – Apr 17
Carrots, beetsSow outdoors · Apr 10 – Apr 24
TomatoesStart indoors · Mar 6 – Mar 20
TomatoesTransplant · May 8 – May 22
Peppers, eggplantStart indoors · Feb 20 – Mar 6
Peppers, eggplantTransplant · May 15 – May 29
BeansSow outdoors · May 8 – May 22
Sweet cornSow outdoors · May 8 – May 22
Cucumbers, squashSow outdoors · May 8 – May 22
Fall lettuce, spinachSow outdoors · Aug 17 – Aug 31
GarlicPlant cloves · Sep 28 – Nov 2
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 1) and first fall frost (Oct 12) 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 97534 came on Feb 23 — about the same time as the 1991–2020 average (Feb 23).

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 O Brien, OR.

Soil in O Brien, OR

The soil mapped at the center of ZIP 97534 is Speaker — gravelly loam, well drained.

TextureGravelly loama good balance for most vegetables
pH5.8moderately acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter3%moderate
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Speaker-Josephine gravelly loams, 35 to 55 percent south 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 97534; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in O Brien, OR

Summer high94 °Faverage high, July
Winter low33 °Faverage low, January
Hot days73days a year at 90 °F or more
Freezing nights75nights a year at 32 °F or less
Growing degree days2,951base 50 °F — the season’s usable heat
Longest day15 h 15 mindaylight on June 21
Shortest day9 h 07 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation71.1 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 49 °F, low 33 °F 49°33° JanFebruary: average high 55 °F, low 33 °F 55°33° FebMarch: average high 60 °F, low 34 °F 60°34° MarApril: average high 67 °F, low 37 °F 67°37° AprMay: average high 76 °F, low 42 °F 76°42° MayJune: average high 84 °F, low 47 °F 84°47° JunJuly: average high 94 °F, low 52 °F 94°52° JulAugust: average high 94 °F, low 49 °F 94°49° AugSeptember: average high 87 °F, low 44 °F 87°44° SepOctober: average high 72 °F, low 39 °F 72°39° OctNovember: average high 55 °F, low 36 °F 55°36° NovDecember: average high 47 °F, low 33 °F 47°33° Dec

Precipitation by month inches

0″2″4″6″8″10″12″14″January: 12.23 in precipitation 12.2 JanFebruary: 9.48 in precipitation 9.5 FebMarch: 9.11 in precipitation 9.1 MarApril: 6.15 in precipitation 6.2 AprMay: 2.80 in precipitation 2.8 MayJune: 0.96 in precipitation 1.0 JunJuly: 0.22 in precipitation 0.2 JulAugust: 0.30 in precipitation 0.3 AugSeptember: 1.18 in precipitation 1.2 SepOctober: 4.80 in precipitation 4.8 OctNovember: 9.61 in precipitation 9.6 NovDecember: 14.25 in precipitation 14.3 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Cave Junction 1 Wnw, OR (10 mi away); precipitation: O'Brien 2 Sw, 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.

975238b
Cave Junction, OR · 6 mi
955438a
Gasquet, CA · 10 mi
975318b
Kerby, OR · 13 mi
975388b
Selma, OR · 20 mi
960868b
Seiad Valley, CA · 23 mi
975448b
Williams, OR · 24 mi
975438b
Wilderville, OR · 26 mi
975278b
Grants Pass, OR · 30 mi

Oregon planting zones →

Questions about 97534

What planting zone is ZIP code 97534?

ZIP code 97534 (O Brien, 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 O Brien, OR?

The median last spring frost (32 °F) near 97534 is May 1; after May 23 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Cave Junction 1 Wnw station.

When is the first frost in O Brien, OR?

The median first fall frost near 97534 is October 12, giving a median frost-free growing season of 161 days.

When should I plant tomatoes in 97534?

Start tomato seeds indoors around Mar 6 – Mar 20 and set transplants outside around May 8 – May 22, one to three weeks after the median last frost.

How much rain and snow does 97534 get?

About 71.1 inches of precipitation a year (NOAA 1991–2020 normals, O'Brien 2 Sw station).

How hot do summers get in O Brien, OR?

The average high peaks at 94 °F in July, with about 73 days a year at 90 °F or more.

What kind of soil does 97534 have?

The USDA soil survey maps Speaker at the center of ZIP 97534: gravelly loam, well drained, pH about 5.8 (moderately acidic).

Did spring come early in O Brien, OR in 2026?

Spring leaf-out near 97534 came on Feb 23 in 2026, about the same as the 1991–2020 average (Feb 23), according to the USA National Phenology Network Spring Index.

What kind of onions grow in O Brien, OR?

Long-day onions: the longest day near 97534 is 15 h 15 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).