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

Planting zone for 99738 — Eagle, AK

ZIP code 99738 (Eagle, Southeast Fairbanks Census Area County) is in USDA zone 2b: the coldest winter night averages −45 to −40 °F. The median last spring frost is May 29 and the first fall frost August 23.

Where ZIP 99738 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.

Zone2b−45 to −40 °F

Coldest night−42.8 to −40 °C

Last frostMay 29

First frostAug 23

2012 zone1b

Was 1b 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 2b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Eagle, 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 Eagle, AK

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 29median — 50% chance of a later frost

Safe for tender plantsJune 11only 10% chance of frost after

First fall frostAugust 23median — 10% chance by Aug 8

Growing season86 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 18 and returns around September 3.

From the NOAA station Eagle, AK — 49 miles away, elevation 850 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 99738

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 17 – May 1

SpinachSow outdoors · Apr 17 – May 8

Broccoli, cabbageStart indoors · Mar 20 – Apr 3

Broccoli, cabbageTransplant · May 8 – May 22

Onion setsPlant outdoors · May 1 – May 15

PotatoesPlant outdoors · May 8 – May 22

LettuceSow outdoors · May 1 – May 15

Carrots, beetsSow outdoors · May 8 – May 22

TomatoesStart indoors · Apr 3 – Apr 17

TomatoesTransplant · Jun 5 – Jun 19

Peppers, eggplantStart indoors · Mar 20 – Apr 3

Peppers, eggplantTransplant · Jun 12 – Jun 26

BeansSow outdoors · Jun 5 – Jun 19

Sweet cornSow outdoors · Jun 5 – Jun 19

Cucumbers, squashSow outdoors · Jun 5 – Jun 19

Fall lettuce, spinachSow outdoors · Jun 28 – Jul 12

GarlicPlant cloves · Aug 9 – Sep 13

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 29) and first fall frost (Aug 23) 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 2b in Alaska

45 plants native to Alaska, recorded in Alaska, and rated by the USDA to survive −45 °F or colder — the bottom of zone 2b. 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 Eagle, AK.

Soil in Eagle, AK

The soil mapped at the center of ZIP 99738 is D31-Boreal taiga silty colluvial slopes, frozen — slightly decomposed plant material, poorly drained.

TextureSlightly decomposed plant materialtop layer

DrainagePoorly drainedconsider raised beds

Organic matter80%high

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Boreal Hills with Extensive Permafrost.

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 99738; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Eagle, AK

Summer high73 °Faverage high, July

Winter low−17 °Faverage low, January

Hot days1days a year at 90 °F or more

Freezing nights247nights a year at 32 °F or less

Growing degree days824base 50 °F — the season’s usable heat

Longest day22 h 15 mindaylight on June 21

Shortest day3 h 28 mindaylight on December 21

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

Precipitation14.3 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: Eagle, AK (49 mi away); precipitation: American Creek, AK (48 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

4 of the 4 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

Chalkyitsik, AK · 108 mi

997802a

Tok, AK · 110 mi

Alaska planting zones →

Questions about 99738

What planting zone is ZIP code 99738?

ZIP code 99738 (Eagle, AK) is in USDA hardiness zone 2b on the 2023 map: the coldest night of an average winter reaches −45 to −40 °F (−42.8 to −40 °C).

When is the last frost in Eagle, AK?

The median last spring frost (32 °F) near 99738 is May 29; after June 11 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Eagle station.

When is the first frost in Eagle, AK?

The median first fall frost near 99738 is August 23, giving a median frost-free growing season of 86 days.

When should I plant tomatoes in 99738?

Start tomato seeds indoors around Apr 3 – Apr 17 and set transplants outside around Jun 5 – Jun 19, one to three weeks after the median last frost.

How much rain and snow does 99738 get?

About 14.3 inches of precipitation a year (NOAA 1991–2020 normals, American Creek station).

How hot do summers get in Eagle, AK?

The average high peaks at 73 °F in July, with about 1 days a year at 90 °F or more.

What kind of soil does 99738 have?

The USDA soil survey maps D31-Boreal taiga silty colluvial slopes, frozen at the center of ZIP 99738: slightly decomposed plant material, poorly drained.

What kind of onions grow in Eagle, AK?

Long-day onions: the longest day near 99738 is 22 h 15 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 99738 change?

Yes. The 2012 USDA map put 99738 in zone 1b; the 2023 map puts it in zone 2b. The newer map uses 1991–2020 data and more weather stations.