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

Planting zone for Sun Valley, ID

Sun Valley, ID is in USDA zone 5b across its 2 ZIP codes. The median last spring frost is May 13 and the first fall frost October 2.

Sun Valley on the zone map

Outlined: its 2 ZIP code areas · 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

ZIP codes2

Last frostMay 13

First frostOct 2

Growing season139 days

5b 2 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Sun Valley, 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 Sun Valley, ID

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 13median — 50% chance of a later frost

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

First fall frostOctober 2median — 10% chance by Sep 15

Growing season139 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 28 and returns around October 14.

From the NOAA station Bellevue, ID, elevation 5,194 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 Sun Valley

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 1 – Apr 15

SpinachSow outdoors · Apr 1 – Apr 22

Broccoli, cabbageStart indoors · Mar 4 – Mar 18

Broccoli, cabbageTransplant · Apr 22 – May 6

Onion setsPlant outdoors · Apr 15 – Apr 29

PotatoesPlant outdoors · Apr 22 – May 6

LettuceSow outdoors · Apr 15 – Apr 29

Carrots, beetsSow outdoors · Apr 22 – May 6

TomatoesStart indoors · Mar 18 – Apr 1

TomatoesTransplant · May 20 – Jun 3

Peppers, eggplantStart indoors · Mar 4 – Mar 18

Peppers, eggplantTransplant · May 27 – Jun 10

BeansSow outdoors · May 20 – Jun 3

Sweet cornSow outdoors · May 20 – Jun 3

Cucumbers, squashSow outdoors · May 20 – Jun 3

Fall lettuce, spinachSow outdoors · Aug 7 – Aug 21

GarlicPlant cloves · Sep 18 – Oct 23

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 13) and first fall frost (Oct 2) 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 83353 came on Apr 9 — 21 days earlier than the 1991–2020 average (Apr 30).

average
Apr 302026
Apr 9

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 Sun Valley, ID.

Soil in Sun Valley, ID

The soil mapped at the center of ZIP 83353 is Povey — gravelly loam, well drained.

TextureGravelly loama good balance for most vegetables

pH7.0neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter2.5%moderate

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Povey-Vitale association, 30 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 83353; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Sun Valley, ID

Summer high80 °Faverage high, July

Winter low8 °Faverage low, January

Hot days4days a year at 90 °F or more

Freezing nights229nights a year at 32 °F or less

Growing degree days1,127base 50 °F — the season’s usable heat

Longest day15 h 27 mindaylight on June 21

Shortest day8 h 55 mindaylight on December 21

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

Precipitation17.3 inper year, rain and melted snow

Snowfall102 inper year

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Ketchum Rs, ID (2 mi away); precipitation: Ketchum Rs, ID (2 mi away). Daylight is calculated from latitude.

ZIP codes in Sun Valley

Idaho planting zones →

Questions about Sun Valley

What planting zone is Sun Valley, ID?

Sun Valley, ID is in USDA hardiness zone 5b on the 2023 map (5b: −15 to −10 °F).

When is the last frost in Sun Valley, ID?

The median last spring frost is May 13 and the median first fall frost is October 2 (NOAA 1991–2020 normals, Bellevue station).

When can I plant a garden in Sun Valley, ID?

Cool-season crops like peas and spinach go in around Apr 1 – Apr 22; tomatoes, peppers, beans and squash after about May 20, once frost risk has passed.

What kind of onions grow in Sun Valley, ID?

Long-day onions: the longest day is 15 h 27 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

How much rain and snow does Sun Valley, ID get?

About 17.3 inches of precipitation a year and 102 inches of snowfall (NOAA 1991–2020 normals).