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

Planting zone for Jber, AK

Jber, AK is in USDA zone 5a across its 2 ZIP codes. The median last spring frost is May 9 and the first fall frost September 26.

Jber 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.

Zone5a−20 to −15 °F

ZIP codes2

Last frostMay 9

First frostSep 26

Growing season138 days

5a 2 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Jber, AK…

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 Jber, AK

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 9median — 50% chance of a later frost

Safe for tender plantsMay 22only 10% chance of frost after

First fall frostSeptember 26median — 10% chance by Sep 9

Growing season138 daysfrost-free, median

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

From the NOAA station Ft Richardson Wtp, AK, elevation 469 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 Jber

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 28 – Apr 11

SpinachSow outdoors · Mar 28 – Apr 18

Broccoli, cabbageStart indoors · Feb 28 – Mar 14

Broccoli, cabbageTransplant · Apr 18 – May 2

Onion setsPlant outdoors · Apr 11 – Apr 25

PotatoesPlant outdoors · Apr 18 – May 2

LettuceSow outdoors · Apr 11 – Apr 25

Carrots, beetsSow outdoors · Apr 18 – May 2

TomatoesStart indoors · Mar 14 – Mar 28

TomatoesTransplant · May 16 – May 30

Peppers, eggplantStart indoors · Feb 28 – Mar 14

Peppers, eggplantTransplant · May 23 – Jun 6

BeansSow outdoors · May 16 – May 30

Sweet cornSow outdoors · May 16 – May 30

Cucumbers, squashSow outdoors · May 16 – May 30

Fall lettuce, spinachSow outdoors · Aug 1 – Aug 15

GarlicPlant cloves · Sep 12 – Oct 17

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 9) and first fall frost (Sep 26) 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.

Native plants for zone 5a in Alaska

275 plants native to Alaska, recorded in Alaska, 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 Jber, AK.

Soil in Jber, AK

The soil mapped at the center of ZIP 99505 is Kashwitna — moderately decomposed plant material, well drained.

TextureModerately decomposed plant materialtop layer

pH4.4strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter55%high

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Kashwitna-Kichatna complex, 0 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 99505; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Jber, AK

Summer high66 °Faverage high, July

Winter low8 °Faverage low, January

Hot days0days a year at 90 °F or more

Freezing nights198nights a year at 32 °F or less

Growing degree days668base 50 °F — the season’s usable heat

Longest day19 h 24 mindaylight on June 21

Shortest day5 h 26 mindaylight on December 21

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

Precipitation15.7 inper year, rain and melted snow

Snowfall59 inper year

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Ft Richardson Wtp, AK (4 mi away); precipitation: Ft Richardson Wtp, AK (4 mi away). Daylight is calculated from latitude.

ZIP codes in Jber

Alaska planting zones →

Questions about Jber

What planting zone is Jber, AK?

Jber, AK is in USDA hardiness zone 5a on the 2023 map (5a: −20 to −15 °F).

When is the last frost in Jber, AK?

The median last spring frost is May 9 and the median first fall frost is September 26 (NOAA 1991–2020 normals, Ft Richardson Wtp station).

When can I plant a garden in Jber, AK?

Cool-season crops like peas and spinach go in around Mar 28 – Apr 18; tomatoes, peppers, beans and squash after about May 16, once frost risk has passed.

What kind of onions grow in Jber, AK?

Long-day onions: the longest day is 19 h 24 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

How much rain and snow does Jber, AK get?

About 15.7 inches of precipitation a year and 59 inches of snowfall (NOAA 1991–2020 normals).