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

Planting zone for 83337 — Hill City, ID

ZIP code 83337 (Hill City, Camas County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is June 16 and the first fall frost September 6.

Where ZIP 83337 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.

Zone5a−20 to −15 °F

Coldest night−28.9 to −26.1 °C

Last frostJun 16

First frostSep 6

2012 zone4b

Was 4b 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 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Hill City, 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 Hill City, ID

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostJune 16median — 50% chance of a later frost

Safe for tender plantsJuly 3only 10% chance of frost after

First fall frostSeptember 6median — 10% chance by Aug 20

Growing season80 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 30 and returns around September 18.

From the NOAA station Hill City 1 W, ID — 7 miles away, elevation 5,102 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 83337

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · May 5 – May 19

SpinachSow outdoors · May 5 – May 26

Broccoli, cabbageStart indoors · Apr 7 – Apr 21

Broccoli, cabbageTransplant · May 26 – Jun 9

Onion setsPlant outdoors · May 19 – Jun 2

PotatoesPlant outdoors · May 26 – Jun 9

LettuceSow outdoors · May 19 – Jun 2

Carrots, beetsSow outdoors · May 26 – Jun 9

TomatoesStart indoors · Apr 21 – May 5

TomatoesTransplant · Jun 23 – Jul 7

Peppers, eggplantStart indoors · Apr 7 – Apr 21

Peppers, eggplantTransplant · Jun 30 – Jul 14

BeansSow outdoors · Jun 23 – Jul 7

Sweet cornSow outdoors · Jun 23 – Jul 7

Cucumbers, squashSow outdoors · Jun 23 – Jul 7

Fall lettuce, spinachSow outdoors · Jul 12 – Jul 26

GarlicPlant cloves · Aug 23 – Sep 27

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 16) and first fall frost (Sep 6) 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 83337 came on Mar 21 — 30 days earlier than the 1991–2020 average (Apr 20).

average
Apr 202026
Mar 21

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 5a in Idaho

536 plants native to the lower 48 states, recorded in Idaho, and rated by the USDA to survive −20 °F or colder — the bottom of zone 5a. 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 Hill City, ID.

Soil in Hill City, ID

The soil mapped at the center of ZIP 83337 is Roanhide — sandy loam, well drained.

TextureSandy loamdrains and warms fast; dries out and needs more feeding

pH6.7neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter2%moderate

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Roanhide-Bauscher-Schoolhouse association, 10 to 60 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 83337; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Hill City, ID

Summer high85 °Faverage high, July

Winter low9 °Faverage low, January

Hot days16days a year at 90 °F or more

Freezing nights212nights a year at 32 °F or less

Growing degree days1,547base 50 °F — the season’s usable heat

Longest day15 h 23 mindaylight on June 21

Shortest day8 h 58 mindaylight on December 21

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

Precipitation14 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: Hill City 1 W, ID (7 mi away); precipitation: Hill City 1 W, ID (7 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

833225a

Corral, ID · 11 mi

836337a

King Hill, ID · 13 mi

836237a

Glenns Ferry, ID · 18 mi

833147a

Bliss, ID · 20 mi

836476b

Mountain Home, ID · 22 mi

833276a

Fairfield, ID · 27 mi

Idaho planting zones →

Questions about 83337

What planting zone is ZIP code 83337?

ZIP code 83337 (Hill City, ID) is in USDA hardiness zone 5a on the 2023 map: the coldest night of an average winter reaches −20 to −15 °F (−28.9 to −26.1 °C).

When is the last frost in Hill City, ID?

The median last spring frost (32 °F) near 83337 is June 16; after July 3 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Hill City 1 W station.

When is the first frost in Hill City, ID?

The median first fall frost near 83337 is September 6, giving a median frost-free growing season of 80 days.

When should I plant tomatoes in 83337?

Start tomato seeds indoors around Apr 21 – May 5 and set transplants outside around Jun 23 – Jul 7, one to three weeks after the median last frost.

How much rain and snow does 83337 get?

About 14 inches of precipitation a year (NOAA 1991–2020 normals, Hill City 1 W station).

How hot do summers get in Hill City, ID?

The average high peaks at 85 °F in July, with about 16 days a year at 90 °F or more.

What kind of soil does 83337 have?

The USDA soil survey maps Roanhide at the center of ZIP 83337: sandy loam, well drained, pH about 6.7 (neutral).

Did spring come early in Hill City, ID in 2026?

Spring leaf-out near 83337 came on Mar 21 in 2026, 30 days earlier than the 1991–2020 average (Apr 20), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Hill City, ID?

Long-day onions: the longest day near 83337 is 15 h 23 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 83337 change?

Yes. The 2012 USDA map put 83337 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.