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

Planting zone for 83278 — Stanley, ID

ZIP code 83278 (Stanley, Custer County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is May 21 and the first fall frost September 18.

Where ZIP 83278 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.

Zone5b−15 to −10 °F

Coldest night−26.1 to −23.3 °C

Last frostMay 21

First frostSep 18

2012 zone5a

Was 5a on the 2012 map — half a zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 5b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Stanley, ID…

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 Stanley, ID

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostMay 21median — 50% chance of a later frost

Safe for tender plantsJune 13only 10% chance of frost after

First fall frostSeptember 18median — 10% chance by Sep 3

Growing season115 daysfrost-free, median

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

From the NOAA station Middle Fork Lodge, ID — 28 miles away, elevation 4,482 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 83278

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 9 – Apr 23

SpinachSow outdoors · Apr 9 – Apr 30

Broccoli, cabbageStart indoors · Mar 12 – Mar 26

Broccoli, cabbageTransplant · Apr 30 – May 14

Onion setsPlant outdoors · Apr 23 – May 7

PotatoesPlant outdoors · Apr 30 – May 14

LettuceSow outdoors · Apr 23 – May 7

Carrots, beetsSow outdoors · Apr 30 – May 14

TomatoesStart indoors · Mar 26 – Apr 9

TomatoesTransplant · May 28 – Jun 11

Peppers, eggplantStart indoors · Mar 12 – Mar 26

Peppers, eggplantTransplant · Jun 4 – Jun 18

BeansSow outdoors · May 28 – Jun 11

Sweet cornSow outdoors · May 28 – Jun 11

Cucumbers, squashSow outdoors · May 28 – Jun 11

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 21) 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 83278 came on May 3 — 13 days earlier than the 1991–2020 average (May 16).

average
May 162026
May 3

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 5b in Idaho

553 plants native to the lower 48 states, recorded in Idaho, and rated by the USDA to survive −15 °F or colder — the bottom of zone 5b. Each links to its USDA PLANTS profile.

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 Stanley, ID.

Soil in Stanley, ID

The soil mapped at the center of ZIP 83278 is Xeric Haplocryepts family — slightly decomposed plant material, well drained.

TextureSlightly decomposed plant materialtop layer

pH5.0strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter75%high

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Xeric Haplocryepts-Typic Haplocryepts-Typic Haplocryolls families complex, 25 to 70 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 83278; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Stanley, ID

Summer high80 °Faverage high, July

Winter low−3 °Faverage low, January

Hot days3days a year at 90 °F or more

Freezing nights294nights a year at 32 °F or less

Growing degree days553base 50 °F — the season’s usable heat

Longest day15 h 32 mindaylight on June 21

Shortest day8 h 51 mindaylight on December 21

Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)

Precipitation18.2 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Stanley, ID (10 mi away); precipitation: Stanley, ID (10 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.

Sun Valley, ID · 51 mi

833545b

Sun Valley, ID · 52 mi

Idaho planting zones →

Questions about 83278

What planting zone is ZIP code 83278?

ZIP code 83278 (Stanley, ID) is in USDA hardiness zone 5b on the 2023 map: the coldest night of an average winter reaches −15 to −10 °F (−26.1 to −23.3 °C).

When is the last frost in Stanley, ID?

The median last spring frost (32 °F) near 83278 is May 21; after June 13 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Middle Fork Lodge station.

When is the first frost in Stanley, ID?

The median first fall frost near 83278 is September 18, giving a median frost-free growing season of 115 days.

When should I plant tomatoes in 83278?

Start tomato seeds indoors around Mar 26 – Apr 9 and set transplants outside around May 28 – Jun 11, one to three weeks after the median last frost.

How much rain and snow does 83278 get?

About 18.2 inches of precipitation a year (NOAA 1991–2020 normals, Stanley station).

How hot do summers get in Stanley, ID?

The average high peaks at 80 °F in July, with about 3 days a year at 90 °F or more.

What kind of soil does 83278 have?

The USDA soil survey maps Xeric Haplocryepts family at the center of ZIP 83278: slightly decomposed plant material, well drained, pH about 5.0 (strongly acidic).

Did spring come early in Stanley, ID in 2026?

Spring leaf-out near 83278 came on May 3 in 2026, 13 days earlier than the 1991–2020 average (May 16), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Stanley, ID?

Long-day onions: the longest day near 83278 is 15 h 32 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 83278 change?

Yes. The 2012 USDA map put 83278 in zone 5a; the 2023 map puts it in zone 5b. The newer map uses 1991–2020 data and more weather stations.