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

Planting zone for 83530 — Grangeville, ID

ZIP code 83530 (Grangeville, Idaho County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is May 9 and the first fall frost October 3.

Where ZIP 83530 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 9

First frostOct 3

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 Grangeville, 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 Grangeville, ID

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 9median — 50% chance of a later frost

Safe for tender plantsMay 27only 10% chance of frost after

First fall frostOctober 3median — 10% chance by Sep 14

Growing season146 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 22 and returns around October 15.

From the NOAA station Grangeville, ID — 5 miles away, elevation 3,301 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 83530

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 28 – Apr 11

SpinachSow outdoors · Mar 28 – Apr 18

Broccoli, cabbageStart indoors · Feb 28 – Mar 14

Broccoli, cabbageTransplant · Apr 18 – May 2

Onion setsPlant outdoors · Apr 11 – Apr 25

PotatoesPlant outdoors · Apr 18 – May 2

LettuceSow outdoors · Apr 11 – Apr 25

Carrots, beetsSow outdoors · Apr 18 – May 2

TomatoesStart indoors · Mar 14 – Mar 28

TomatoesTransplant · May 16 – May 30

Peppers, eggplantStart indoors · Feb 28 – Mar 14

Peppers, eggplantTransplant · May 23 – Jun 6

BeansSow outdoors · May 16 – May 30

Sweet cornSow outdoors · May 16 – May 30

Cucumbers, squashSow outdoors · May 16 – May 30

Fall lettuce, spinachSow outdoors · Aug 8 – Aug 22

GarlicPlant cloves · Sep 19 – Oct 24

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 9) and first fall frost (Oct 3) 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 83530 came on Mar 20 — 17 days earlier than the 1991–2020 average (Apr 6).

average
Apr 62026
Mar 20

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 Idaho

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

Soil in Grangeville, ID

The soil mapped at the center of ZIP 83530 is Klickson — moderately decomposed plant material, well drained.

TextureModerately decomposed plant materialtop layer

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

DrainageWell drainednatural drainage class

Organic matter70%high

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Klickson-Suloaf 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 83530; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Grangeville, ID

Summer high83 °Faverage high, August

Winter low24 °Faverage low, December

Hot days14days a year at 90 °F or more

Freezing nights145nights a year at 32 °F or less

Growing degree days1,888base 50 °F — the season’s usable heat

Longest day15 h 45 mindaylight on June 21

Shortest day8 h 39 mindaylight on December 21

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

Precipitation23.5 inper year, rain and melted snow

Snowfall39 inper year; 38 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Grangeville, ID (5 mi away); precipitation: Grangeville, ID (5 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.

Greencreek, ID · 17 mi

835547a

White Bird, ID · 20 mi

835367a

Kamiah, ID · 20 mi

835226b

Cottonwood, ID · 22 mi

835266a

Ferdinand, ID · 25 mi

835427a

Lucile, ID · 29 mi

Idaho planting zones →

Questions about 83530

What planting zone is ZIP code 83530?

ZIP code 83530 (Grangeville, ID) 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 Grangeville, ID?

The median last spring frost (32 °F) near 83530 is May 9; after May 27 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Grangeville station.

When is the first frost in Grangeville, ID?

The median first fall frost near 83530 is October 3, giving a median frost-free growing season of 146 days.

When should I plant tomatoes in 83530?

Start tomato seeds indoors around Mar 14 – Mar 28 and set transplants outside around May 16 – May 30, one to three weeks after the median last frost.

How much rain and snow does 83530 get?

About 23.5 inches of precipitation a year and 39 inches of snowfall (NOAA 1991–2020 normals, Grangeville station).

How hot do summers get in Grangeville, ID?

The average high peaks at 83 °F in August, with about 14 days a year at 90 °F or more.

What kind of soil does 83530 have?

The USDA soil survey maps Klickson at the center of ZIP 83530: moderately decomposed plant material, well drained, pH about 5.0 (strongly acidic).

Did spring come early in Grangeville, ID in 2026?

Spring leaf-out near 83530 came on Mar 20 in 2026, 17 days earlier than the 1991–2020 average (Apr 6), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Grangeville, ID?

Long-day onions: the longest day near 83530 is 15 h 45 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).