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

Planting zone for 99826 — Gustavus, AK

ZIP code 99826 (Gustavus, Hoonah-Angoon County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is May 30 and the first fall frost September 16.

Where ZIP 99826 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.

Zone7a0 to 5 °F
Coldest night−17.8 to −15 °C
Last frostMay 30
First frostSep 16
2012 zone6b

Was 6b 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 7a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Gustavus, 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 Gustavus, AK

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 30median — 50% chance of a later frost
Safe for tender plantsJune 22only 10% chance of frost after
First fall frostSeptember 16median — 10% chance by Aug 29
Growing season107 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 12 and returns around October 1.

From the NOAA station Gustavus, AK — 4 miles away, elevation 39 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 99826

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 18 – May 2
SpinachSow outdoors · Apr 18 – May 9
Broccoli, cabbageStart indoors · Mar 21 – Apr 4
Broccoli, cabbageTransplant · May 9 – May 23
Onion setsPlant outdoors · May 2 – May 16
PotatoesPlant outdoors · May 9 – May 23
LettuceSow outdoors · May 2 – May 16
Carrots, beetsSow outdoors · May 9 – May 23
TomatoesStart indoors · Apr 4 – Apr 18
TomatoesTransplant · Jun 6 – Jun 20
Peppers, eggplantStart indoors · Mar 21 – Apr 4
Peppers, eggplantTransplant · Jun 13 – Jun 27
BeansSow outdoors · Jun 6 – Jun 20
Sweet cornSow outdoors · Jun 6 – Jun 20
Cucumbers, squashSow outdoors · Jun 6 – Jun 20
Fall lettuce, spinachSow outdoors · Jul 22 – Aug 5
GarlicPlant cloves · Sep 2 – Oct 7
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 30) and first fall frost (Sep 16) 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 7a in Alaska

289 plants native to Alaska, recorded in Alaska, and rated by the USDA to survive 0 °F or colder — the bottom of zone 7a. Each links to its USDA PLANTS profile.

Trees 16

Alaska cedar75 ft · blooms mid spring · low shade tolerance · to −22 °Fbalsam 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 °Fmountain hemlock125 ft · blooms early summer · low shade tolerance · to −18 °FPacific silver fir165 ft · blooms late spring · low shade tolerance · to −28 °F

Shrubs 50

alpine bearberry0.5 ft · blooms early spring · medium shade tolerance · to −62 °Falpine laurel1 ft · blooms late spring · low shade tolerance · to −28 °FBarclay's willow15 ft · high shade tolerance · to −43 °Fblack crowberry1 ft · blooms mid summer · high shade tolerance · to −43 °Fblack hawthorn15 ft · blooms mid spring · medium shade tolerance · to −47 °Fbog blueberry2 ft · blooms early summer · medium shade tolerance · to −38 °F

Wildflowers & perennials 125

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine aster0.3 ft · blooms early summer · medium shade tolerance · to −28 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °Falpine mountainsorrel1 ft · blooms mid summer · medium shade tolerance · to −43 °Falpine sweetvetch2 ft · blooms early summer · high shade tolerance · to −62 °FAmerican alpine speedwell1 ft · blooms summer · medium shade tolerance · to −28 °F

Grasses 89

Alaska brome5 ft · blooms late spring · low shade tolerance · to −18 °FAlaska oniongrass3 ft · blooms mid spring · low shade tolerance · to −33 °FAlpine Meadow-Foxtail0.5 ft · blooms mid spring · medium shade tolerance · to −33 °Falpine timothy1.4 ft · blooms late spring · medium shade tolerance · to −43 °Farctic bluegrass2 ft · high shade tolerance · to −62 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °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 Gustavus, AK.

Soil in Gustavus, AK

The soil mapped at the center of ZIP 99826 is Gustavus — moderately decomposed plant material, well drained.

TextureModerately decomposed plant materialtop layer
pH4.3strongly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter80%high
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Gustavus-Perouse complex, 0 to 15 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 99826; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Gustavus, AK

Summer high63 °Faverage high, July
Winter low21 °Faverage low, January
Hot days0days a year at 90 °F or more
Freezing nights161nights a year at 32 °F or less
Growing degree days406base 50 °F — the season’s usable heat
Longest day18 h 19 mindaylight on June 21
Shortest day6 h 20 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation62.3 inper year, rain and melted snow
Snowfall72 inper year; 105 days with snow on the ground

Average high and low, by month

10°20°30°40°50°60°70°32 °FJanuary: average high 32 °F, low 21 °F 32°21° JanFebruary: average high 36 °F, low 21 °F 36°21° FebMarch: average high 40 °F, low 23 °F 40°23° MarApril: average high 49 °F, low 29 °F 49°29° AprMay: average high 57 °F, low 35 °F 57°35° MayJune: average high 61 °F, low 42 °F 61°42° JunJuly: average high 63 °F, low 47 °F 63°47° JulAugust: average high 63 °F, low 46 °F 63°46° AugSeptember: average high 57 °F, low 40 °F 57°40° SepOctober: average high 47 °F, low 33 °F 47°33° OctNovember: average high 38 °F, low 26 °F 38°26° NovDecember: average high 34 °F, low 24 °F 34°24° Dec

Precipitation by month inches · ❄ = snowfall

0″2″4″6″8″January: 5.94 in precipitation, 18.1 in snowfall 5.9❄18 JanFebruary: 3.76 in precipitation, 11.4 in snowfall 3.8❄11 FebMarch: 3.17 in precipitation, 11.7 in snowfall 3.2❄12 MarApril: 3.01 in precipitation, 1.8 in snowfall 3.0❄2 AprMay: 2.98 in precipitation 3.0 MayJune: 2.90 in precipitation 2.9 JunJuly: 4.41 in precipitation 4.4 JulAugust: 5.44 in precipitation 5.4 AugSeptember: 8.21 in precipitation 8.2 SepOctober: 8.43 in precipitation, 0.5 in snowfall 8.4❄1 OctNovember: 6.79 in precipitation, 10.8 in snowfall 6.8❄11 NovDecember: 7.25 in precipitation, 18 in snowfall 7.3❄18 Dec

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

Nearby ZIP codes

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

998507a
Juneau, AK · 13 mi
998257a
Elfin Cove, AK · 28 mi
998275b
Haines, AK · 32 mi
998297a
Hoonah, AK · 32 mi
998327a
Pelican, AK · 32 mi
998417a
Tenakee Springs, AK · 33 mi
998217a
Auke Bay, AK · 40 mi
998127a
Juneau, AK · 49 mi

Alaska planting zones →

Questions about 99826

What planting zone is ZIP code 99826?

ZIP code 99826 (Gustavus, AK) is in USDA hardiness zone 7a on the 2023 map: the coldest night of an average winter reaches 0 to 5 °F (−17.8 to −15 °C).

When is the last frost in Gustavus, AK?

The median last spring frost (32 °F) near 99826 is May 30; after June 22 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Gustavus station.

When is the first frost in Gustavus, AK?

The median first fall frost near 99826 is September 16, giving a median frost-free growing season of 107 days.

When should I plant tomatoes in 99826?

Start tomato seeds indoors around Apr 4 – Apr 18 and set transplants outside around Jun 6 – Jun 20, one to three weeks after the median last frost.

How much rain and snow does 99826 get?

About 62.3 inches of precipitation a year and 72 inches of snowfall (NOAA 1991–2020 normals, Gustavus station).

How hot do summers get in Gustavus, AK?

The average high peaks at 63 °F in July, with about 0 days a year at 90 °F or more.

What kind of soil does 99826 have?

The USDA soil survey maps Gustavus at the center of ZIP 99826: moderately decomposed plant material, well drained, pH about 4.3 (strongly acidic).

What kind of onions grow in Gustavus, AK?

Long-day onions: the longest day near 99826 is 18 h 19 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 99826 change?

Yes. The 2012 USDA map put 99826 in zone 6b; the 2023 map puts it in zone 7a. The newer map uses 1991–2020 data and more weather stations.