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

Planting zone for 83805 — Bonners Ferry, ID

ZIP code 83805 (Bonners Ferry, Boundary County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 4 and the first fall frost September 30.

Where ZIP 83805 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.

Zone6a−10 to −5 °F

Coldest night−23.3 to −20.6 °C

Last frostMay 4

First frostSep 30

2012 zone6a

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 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Bonners Ferry, 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 Bonners Ferry, ID

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 4median — 50% chance of a later frost

Safe for tender plantsMay 28only 10% chance of frost after

First fall frostSeptember 30median — 10% chance by Sep 10

Growing season145 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 16 and returns around October 11.

From the NOAA station Porthill 1 Sw, ID — 11 miles away, elevation 1,798 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 83805

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 23 – Apr 6

SpinachSow outdoors · Mar 23 – Apr 13

Broccoli, cabbageStart indoors · Feb 23 – Mar 9

Broccoli, cabbageTransplant · Apr 13 – Apr 27

Onion setsPlant outdoors · Apr 6 – Apr 20

PotatoesPlant outdoors · Apr 13 – Apr 27

LettuceSow outdoors · Apr 6 – Apr 20

Carrots, beetsSow outdoors · Apr 13 – Apr 27

TomatoesStart indoors · Mar 9 – Mar 23

TomatoesTransplant · May 11 – May 25

Peppers, eggplantStart indoors · Feb 23 – Mar 9

Peppers, eggplantTransplant · May 18 – Jun 1

BeansSow outdoors · May 11 – May 25

Sweet cornSow outdoors · May 11 – May 25

Cucumbers, squashSow outdoors · May 11 – May 25

Fall lettuce, spinachSow outdoors · Aug 5 – Aug 19

GarlicPlant cloves · Sep 16 – Oct 21

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 4) and first fall frost (Sep 30) 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 83805 came on Apr 30 — 7 days earlier than the 1991–2020 average (May 7).

average
May 72026
Apr 30

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 6a in Idaho

567 plants native to the lower 48 states, recorded in Idaho, and rated by the USDA to survive −10 °F or colder — the bottom of zone 6a. 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 Bonners Ferry, ID.

Soil in Bonners Ferry, ID

The soil mapped at the center of ZIP 83805 is Andic Humudepts — slightly decomposed plant material, well drained.

TextureSlightly decomposed plant materialtop layer

pH5.5moderately 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: Andic Humudepts-Humic Udivitrands-Pearsoncreek families, dense substratum complex, moderately steep glaciated mountain slopes, granitic geology, south aspects.

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 83805; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Bonners Ferry, ID

Summer high86 °Faverage high, July

Winter low21 °Faverage low, January

Hot days20days a year at 90 °F or more

Freezing nights162nights a year at 32 °F or less

Growing degree days2,018base 50 °F — the season’s usable heat

Longest day16 h 11 mindaylight on June 21

Shortest day8 h 15 mindaylight on December 21

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

Precipitation30.6 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: Porthill 1 Sw, ID (11 mi away); precipitation: Myrtle Creek, ID (8 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

Moyie Springs, ID · 19 mi

Sandpoint, ID · 27 mi

Idaho planting zones →

Questions about 83805

What planting zone is ZIP code 83805?

ZIP code 83805 (Bonners Ferry, ID) is in USDA hardiness zone 6a on the 2023 map: the coldest night of an average winter reaches −10 to −5 °F (−23.3 to −20.6 °C).

When is the last frost in Bonners Ferry, ID?

The median last spring frost (32 °F) near 83805 is May 4; after May 28 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Porthill 1 Sw station.

When is the first frost in Bonners Ferry, ID?

The median first fall frost near 83805 is September 30, giving a median frost-free growing season of 145 days.

When should I plant tomatoes in 83805?

Start tomato seeds indoors around Mar 9 – Mar 23 and set transplants outside around May 11 – May 25, one to three weeks after the median last frost.

How much rain and snow does 83805 get?

About 30.6 inches of precipitation a year (NOAA 1991–2020 normals, Myrtle Creek station).

How hot do summers get in Bonners Ferry, ID?

The average high peaks at 86 °F in July, with about 20 days a year at 90 °F or more.

What kind of soil does 83805 have?

The USDA soil survey maps Andic Humudepts at the center of ZIP 83805: slightly decomposed plant material, well drained, pH about 5.5 (moderately acidic).

Did spring come early in Bonners Ferry, ID in 2026?

Spring leaf-out near 83805 came on Apr 30 in 2026, 7 days earlier than the 1991–2020 average (May 7), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Bonners Ferry, ID?

Long-day onions: the longest day near 83805 is 16 h 11 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).