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

Planting zone for 83342 — Malta, ID

ZIP code 83342 (Malta, Cassia County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is June 1 and the first fall frost September 19.

Where ZIP 83342 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 frostJun 1

First frostSep 19

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 Malta, 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 Malta, ID

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostJune 1median — 50% chance of a later frost

Safe for tender plantsJune 19only 10% chance of frost after

First fall frostSeptember 19median — 10% chance by Sep 2

Growing season111 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 6 and returns around October 2.

From the NOAA station Malta 4 Ese, ID — 11 miles away, elevation 4,590 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 83342

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 20 – May 4

SpinachSow outdoors · Apr 20 – May 11

Broccoli, cabbageStart indoors · Mar 23 – Apr 6

Broccoli, cabbageTransplant · May 11 – May 25

Onion setsPlant outdoors · May 4 – May 18

PotatoesPlant outdoors · May 11 – May 25

LettuceSow outdoors · May 4 – May 18

Carrots, beetsSow outdoors · May 11 – May 25

TomatoesStart indoors · Apr 6 – Apr 20

TomatoesTransplant · Jun 8 – Jun 22

Peppers, eggplantStart indoors · Mar 23 – Apr 6

Peppers, eggplantTransplant · Jun 15 – Jun 29

BeansSow outdoors · Jun 8 – Jun 22

Sweet cornSow outdoors · Jun 8 – Jun 22

Cucumbers, squashSow outdoors · Jun 8 – Jun 22

Fall lettuce, spinachSow outdoors · Jul 25 – Aug 8

GarlicPlant cloves · Sep 5 – Oct 10

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 1) and first fall frost (Sep 19) 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 83342 came on Mar 20 — 21 days earlier than the 1991–2020 average (Apr 10).

average
Apr 102026
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 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 Malta, ID.

Soil in Malta, ID

The soil mapped at the center of ZIP 83342 is Bahem — silt loam, well drained.

TextureSilt loama good balance for most vegetables

pH8.2alkaline; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter1.5%low — add compost

Hydrologic groupBwater soaks in moderately

Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Bahem silt loam, 1 to 3 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 83342; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Malta, ID

Summer high90 °Faverage high, July

Winter low18 °Faverage low, January

Hot days39days a year at 90 °F or more

Freezing nights173nights a year at 32 °F or less

Growing degree days2,173base 50 °F — the season’s usable heat

Longest day15 h 16 mindaylight on June 21

Shortest day9 h 06 mindaylight on December 21

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

Precipitation9.6 inper year, rain and melted snow

Snowfall12 inper year

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Malta 4 Ese, ID (11 mi away); precipitation: Malta, ID (13 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.

Park Valley, UT · 26 mi

832716a

Rockland, ID · 27 mi

843366a

Snowville, UT · 27 mi

832436a

Holbrook, ID · 30 mi

832116a

American Falls, ID · 36 mi

Idaho planting zones →

Questions about 83342

What planting zone is ZIP code 83342?

ZIP code 83342 (Malta, 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 Malta, ID?

The median last spring frost (32 °F) near 83342 is June 1; after June 19 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Malta 4 Ese station.

When is the first frost in Malta, ID?

The median first fall frost near 83342 is September 19, giving a median frost-free growing season of 111 days.

When should I plant tomatoes in 83342?

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

How much rain and snow does 83342 get?

About 9.6 inches of precipitation a year and 12 inches of snowfall (NOAA 1991–2020 normals, Malta station).

How hot do summers get in Malta, ID?

The average high peaks at 90 °F in July, with about 39 days a year at 90 °F or more.

What kind of soil does 83342 have?

The USDA soil survey maps Bahem at the center of ZIP 83342: silt loam, well drained, pH about 8.2 (alkaline).

Did spring come early in Malta, ID in 2026?

Spring leaf-out near 83342 came on Mar 20 in 2026, 21 days earlier than the 1991–2020 average (Apr 10), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Malta, ID?

Long-day onions: the longest day near 83342 is 15 h 16 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).