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

Planting zone for 83239 — Georgetown, ID

ZIP code 83239 (Georgetown, Bear Lake County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is June 17 and the first fall frost September 3.

Where ZIP 83239 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.

Zone5b−15 to −10 °F

Coldest night−26.1 to −23.3 °C

Last frostJun 17

First frostSep 3

2012 zone4b

Was 4b on the 2012 map — a full zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 5b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Georgetown, 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 Georgetown, ID

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostJune 17median — 50% chance of a later frost

Safe for tender plantsJuly 4only 10% chance of frost after

First fall frostSeptember 3median — 10% chance by Aug 18

Growing season77 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 25 and returns around September 16.

From the NOAA station Bern, ID — 14 miles away, elevation 5,965 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 83239

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · May 6 – May 20

SpinachSow outdoors · May 6 – May 27

Broccoli, cabbageStart indoors · Apr 8 – Apr 22

Broccoli, cabbageTransplant · May 27 – Jun 10

Onion setsPlant outdoors · May 20 – Jun 3

PotatoesPlant outdoors · May 27 – Jun 10

LettuceSow outdoors · May 20 – Jun 3

Carrots, beetsSow outdoors · May 27 – Jun 10

TomatoesStart indoors · Apr 22 – May 6

TomatoesTransplant · Jun 24 – Jul 8

Peppers, eggplantStart indoors · Apr 8 – Apr 22

Peppers, eggplantTransplant · Jul 1 – Jul 15

BeansSow outdoors · Jun 24 – Jul 8

Sweet cornSow outdoors · Jun 24 – Jul 8

Cucumbers, squashSow outdoors · Jun 24 – Jul 8

Fall lettuce, spinachSow outdoors · Jul 9 – Jul 23

GarlicPlant cloves · Aug 20 – Sep 24

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 17) and first fall frost (Sep 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 83239 came on Apr 23 — 12 days earlier than the 1991–2020 average (May 5).

average
May 52026
Apr 23

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 Georgetown, ID.

Soil in Georgetown, ID

The soil mapped at the center of ZIP 83239 is Farlow — 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 groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Farlow family-Starley family, extremely stony surface-Sparky complex, 40 to 70 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 83239; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Georgetown, ID

Summer high85 °Faverage high, July

Winter low7 °Faverage low, January

Hot days16days a year at 90 °F or more

Freezing nights217nights a year at 32 °F or less

Growing degree days1,463base 50 °F — the season’s usable heat

Longest day15 h 18 mindaylight on June 21

Shortest day9 h 03 mindaylight on December 21

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

Precipitation32.9 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: Bern, ID (14 mi away); precipitation: Slug Creek Divide, ID (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

832205a

Bern, ID · 13 mi

832545a

Montpelier, ID · 14 mi

832765a

Soda Springs, ID · 16 mi

Idaho planting zones →

Questions about 83239

What planting zone is ZIP code 83239?

ZIP code 83239 (Georgetown, ID) is in USDA hardiness zone 5b on the 2023 map: the coldest night of an average winter reaches −15 to −10 °F (−26.1 to −23.3 °C).

When is the last frost in Georgetown, ID?

The median last spring frost (32 °F) near 83239 is June 17; after July 4 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Bern station.

When is the first frost in Georgetown, ID?

The median first fall frost near 83239 is September 3, giving a median frost-free growing season of 77 days.

When should I plant tomatoes in 83239?

Start tomato seeds indoors around Apr 22 – May 6 and set transplants outside around Jun 24 – Jul 8, one to three weeks after the median last frost.

How much rain and snow does 83239 get?

About 32.9 inches of precipitation a year (NOAA 1991–2020 normals, Slug Creek Divide station).

How hot do summers get in Georgetown, 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 83239 have?

The USDA soil survey maps Farlow at the center of ZIP 83239: moderately decomposed plant material, well drained, pH about 5.0 (strongly acidic).

Did spring come early in Georgetown, ID in 2026?

Spring leaf-out near 83239 came on Apr 23 in 2026, 12 days earlier than the 1991–2020 average (May 5), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Georgetown, ID?

Long-day onions: the longest day near 83239 is 15 h 18 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 83239 change?

Yes. The 2012 USDA map put 83239 in zone 4b; the 2023 map puts it in zone 5b. The newer map uses 1991–2020 data and more weather stations.