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

Planting zone for 99776 — Tanacross, AK

ZIP code 99776 (Tanacross, Southeast Fairbanks Census Area County) is in USDA zone 1b: the coldest winter night averages −55 to −50 °F. The median last spring frost is June 3 and the first fall frost August 27.

Where ZIP 99776 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.

Zone1b−55 to −50 °F
Coldest night−48.3 to −45.6 °C
Last frostJun 3
First frostAug 27
2012 zone1a

Was 1a 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 1b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Tanacross, 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 Tanacross, AK

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostJune 3median — 50% chance of a later frost
Safe for tender plantsJuly 13only 10% chance of frost after
First fall frostAugust 27median — 10% chance by Aug 11
Growing season79 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 22 and returns around September 6.

From the NOAA station Tok #2, AK — 15 miles away, elevation 1,657 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 99776

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 22 – May 6
SpinachSow outdoors · Apr 22 – May 13
Broccoli, cabbageStart indoors · Mar 25 – Apr 8
Broccoli, cabbageTransplant · May 13 – May 27
Onion setsPlant outdoors · May 6 – May 20
PotatoesPlant outdoors · May 13 – May 27
LettuceSow outdoors · May 6 – May 20
Carrots, beetsSow outdoors · May 13 – May 27
TomatoesStart indoors · Apr 8 – Apr 22
TomatoesTransplant · Jun 10 – Jun 24
Peppers, eggplantStart indoors · Mar 25 – Apr 8
Peppers, eggplantTransplant · Jun 17 – Jul 1
BeansSow outdoors · Jun 10 – Jun 24
Sweet cornSow outdoors · Jun 10 – Jun 24
Cucumbers, squashSow outdoors · Jun 10 – Jun 24
Fall lettuce, spinachSow outdoors · Jul 2 – Jul 16
GarlicPlant cloves · Aug 13 – Sep 17
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 3) and first fall frost (Aug 27) 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 1b in Alaska

37 plants native to Alaska, recorded in Alaska, and rated by the USDA to survive −55 °F or colder — the bottom of zone 1b. Each links to its USDA PLANTS profile.

Trees 7

balsam poplar80 ft · blooms late spring · high shade tolerance · to −79 °Fblack spruce65 ft · blooms late spring · low shade tolerance · to −79 °Flodgepole pine99 ft · blooms mid summer · high shade tolerance · to −70 °Fpaper birch70 ft · blooms mid spring · high shade tolerance · to −62 °Fquaking aspen65 ft · blooms mid spring · high shade tolerance · to −70 °Ftamarack80 ft · blooms mid spring · high shade tolerance · to −79 °F

Shrubs 15

alpine bearberry0.5 ft · blooms early spring · medium shade tolerance · to −62 °Fhalberd willow3 ft · blooms early summer · to −62 °FLapland rosebay3 ft · blooms late spring · low shade tolerance · to −62 °Flingonberry0.5 ft · blooms summer · high shade tolerance · to −62 °Fmarsh Labrador tea0.5 ft · blooms summer · to −62 °Fnetleaf willow0.2 ft · blooms early summer · to −62 °F

Wildflowers & perennials 11

alpine sweetvetch2 ft · blooms early summer · high shade tolerance · to −62 °Farctic dock1 ft · blooms summer · high shade tolerance · to −62 °Farctic lupine2 ft · blooms spring · medium shade tolerance · to −62 °Farctic raspberry1 ft · blooms summer · high shade tolerance · to −62 °Feightpetal mountain-avens0.3 ft · blooms late spring · medium shade tolerance · to −62 °Fhigh northern buttercup1 ft · blooms summer · high shade tolerance · to −62 °F

Grasses 2

arctic bluegrass2 ft · high shade tolerance · to −62 °Flivid sedge1 ft · blooms early summer · high shade tolerance · to −62 °F

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 Tanacross, AK.

Soil in Tanacross, AK

The soil mapped at the center of ZIP 99776 is E28-boreal alpine scrub-gravelly colluvial slopes — slightly decomposed plant material, well drained.

TextureSlightly decomposed plant materialtop layer
DrainageWell drainednatural drainage class
Organic matter75%high
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Interior Alaska Mountains-Boreal Alpine-Rugged Mountains, Acid.

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 99776; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Tanacross, AK

Summer high72 °Faverage high, July
Winter low−20 °Faverage low, January
Hot days1days a year at 90 °F or more
Freezing nights257nights a year at 32 °F or less
Growing degree days672base 50 °F — the season’s usable heat
Longest day20 h 32 mindaylight on June 21
Shortest day4 h 33 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation10.6 inper year, rain and melted snow
Snowfall38 inper year; 198 days with snow on the ground

Average high and low, by month

−30°−20°−10°0°10°20°30°40°50°60°70°80°32 °FJanuary: average high -4 °F, low -20 °F −4°−20° JanFebruary: average high 8 °F, low -13 °F 8°−13° FebMarch: average high 24 °F, low -5 °F 24°−5° MarApril: average high 45 °F, low 18 °F 45°18° AprMay: average high 61 °F, low 31 °F 61°31° MayJune: average high 71 °F, low 42 °F 71°42° JunJuly: average high 72 °F, low 46 °F 72°46° JulAugust: average high 67 °F, low 40 °F 67°40° AugSeptember: average high 54 °F, low 31 °F 54°31° SepOctober: average high 31 °F, low 14 °F 31°14° OctNovember: average high 8 °F, low -8 °F 8°−8° NovDecember: average high -2 °F, low -18 °F −2°−18° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″January: 0.43 in precipitation, 4.9 in snowfall 0.4❄5 JanFebruary: 0.21 in precipitation, 3.5 in snowfall 0.2❄4 FebMarch: 0.20 in precipitation, 3.3 in snowfall 0.2❄3 MarApril: 0.21 in precipitation, 2.4 in snowfall 0.2❄2 AprMay: 0.87 in precipitation, 0.9 in snowfall 0.9❄1 MayJune: 2.37 in precipitation 2.4 JunJuly: 2.29 in precipitation 2.3 JulAugust: 1.32 in precipitation 1.3 AugSeptember: 0.95 in precipitation, 1.8 in snowfall 0.9❄2 SepOctober: 0.55 in precipitation, 4.9 in snowfall 0.6❄5 OctNovember: 0.62 in precipitation, 8.2 in snowfall 0.6❄8 NovDecember: 0.58 in precipitation, 7.7 in snowfall 0.6❄8 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Tok, AK (14 mi away); precipitation: Tok, AK (14 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

995862b
Gakona, AK · 50 mi
997063b
Fairbanks, AK · 60 mi
997642a
Northway, AK · 69 mi
997321b
Chicken, AK · 70 mi

Alaska planting zones →

Questions about 99776

What planting zone is ZIP code 99776?

ZIP code 99776 (Tanacross, AK) is in USDA hardiness zone 1b on the 2023 map: the coldest night of an average winter reaches −55 to −50 °F (−48.3 to −45.6 °C).

When is the last frost in Tanacross, AK?

The median last spring frost (32 °F) near 99776 is June 3; after July 13 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Tok #2 station.

When is the first frost in Tanacross, AK?

The median first fall frost near 99776 is August 27, giving a median frost-free growing season of 79 days.

When should I plant tomatoes in 99776?

Start tomato seeds indoors around Apr 8 – Apr 22 and set transplants outside around Jun 10 – Jun 24, one to three weeks after the median last frost.

How much rain and snow does 99776 get?

About 10.6 inches of precipitation a year and 38 inches of snowfall (NOAA 1991–2020 normals, Tok station).

How hot do summers get in Tanacross, AK?

The average high peaks at 72 °F in July, with about 1 days a year at 90 °F or more.

What kind of soil does 99776 have?

The USDA soil survey maps E28-boreal alpine scrub-gravelly colluvial slopes at the center of ZIP 99776: slightly decomposed plant material, well drained.

What kind of onions grow in Tanacross, AK?

Long-day onions: the longest day near 99776 is 20 h 32 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 99776 change?

Yes. The 2012 USDA map put 99776 in zone 1a; the 2023 map puts it in zone 1b. The newer map uses 1991–2020 data and more weather stations.