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

Planting zone for 99692 — Dutch Harbor, AK

ZIP code 99692 (Dutch Harbor, Aleutians West (CA) County) is in USDA zone 8b: the coldest winter night averages 15 to 20 °F. The median last spring frost is May 6 and the first fall frost October 18.

Where ZIP 99692 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.

Zone8b15 to 20 °F
Coldest night−9.4 to −6.7 °C
Last frostMay 6
First frostOct 18
2012 zone7b

Was 7b 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 8b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Dutch Harbor, 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 Dutch Harbor, AK

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 6median — 50% chance of a later frost
Safe for tender plantsMay 22only 10% chance of frost after
First fall frostOctober 18median — 10% chance by Sep 20
Growing season164 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 19 and returns around November 4.

From the NOAA station Dutch Harbor, AK — within 1 mile, elevation 10 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 99692

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 25 – Apr 8
SpinachSow outdoors · Mar 25 – Apr 15
Broccoli, cabbageStart indoors · Feb 25 – Mar 11
Broccoli, cabbageTransplant · Apr 15 – Apr 29
Onion setsPlant outdoors · Apr 8 – Apr 22
PotatoesPlant outdoors · Apr 15 – Apr 29
LettuceSow outdoors · Apr 8 – Apr 22
Carrots, beetsSow outdoors · Apr 15 – Apr 29
TomatoesStart indoors · Mar 11 – Mar 25
TomatoesTransplant · May 13 – May 27
Peppers, eggplantStart indoors · Feb 25 – Mar 11
Peppers, eggplantTransplant · May 20 – Jun 3
BeansSow outdoors · May 13 – May 27
Sweet cornSow outdoors · May 13 – May 27
Cucumbers, squashSow outdoors · May 13 – May 27
Fall lettuce, spinachSow outdoors · Aug 23 – Sep 6
GarlicPlant cloves · Oct 4 – Nov 8
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 6) and first fall frost (Oct 18) 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 8b in Alaska

294 plants native to Alaska, recorded in Alaska, and rated by the USDA to survive 15 °F or colder — the bottom of zone 8b. 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 52

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 126

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 Dutch Harbor, AK.

Soil in Dutch Harbor, AK

The soil mapped at the center of ZIP 99692 is E26-Maritime herbaceous-ashy slopes — slightly decomposed plant material, well drained.

TextureSlightly decomposed plant materialtop layer
pH6.4slightly 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: Aleutian Islands-Western Alaska Peninsula-Maritime Upland-Rounded Mountains and Hills.

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 99692; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Dutch Harbor, AK

Summer high59 °Faverage high, August
Winter low29 °Faverage low, January
Hot days0days a year at 90 °F or more
Freezing nights112nights a year at 32 °F or less
Growing degree days250base 50 °F — the season’s usable heat
Longest day17 h 07 mindaylight on June 21
Shortest day7 h 23 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation60.1 inper year, rain and melted snow
Snowfall82 inper year; 70 days with snow on the ground

Average high and low, by month

20°30°40°50°60°70°32 °FJanuary: average high 37 °F, low 29 °F 37°29° JanFebruary: average high 39 °F, low 29 °F 39°29° FebMarch: average high 39 °F, low 29 °F 39°29° MarApril: average high 42 °F, low 33 °F 42°33° AprMay: average high 47 °F, low 37 °F 47°37° MayJune: average high 52 °F, low 42 °F 52°42° JunJuly: average high 57 °F, low 47 °F 57°47° JulAugust: average high 59 °F, low 48 °F 59°48° AugSeptember: average high 55 °F, low 44 °F 55°44° SepOctober: average high 48 °F, low 38 °F 48°38° OctNovember: average high 43 °F, low 33 °F 43°33° NovDecember: average high 39 °F, low 31 °F 39°31° Dec

Precipitation by month inches · ❄ = snowfall

0″2″4″6″8″January: 6.79 in precipitation, 22 in snowfall 6.8❄22 JanFebruary: 5.18 in precipitation, 14.2 in snowfall 5.2❄14 FebMarch: 4.65 in precipitation, 16.5 in snowfall 4.7❄17 MarApril: 3.47 in precipitation, 6.3 in snowfall 3.5❄6 AprMay: 4.20 in precipitation, 0.2 in snowfall 4.2 MayJune: 2.52 in precipitation 2.5 JunJuly: 2.30 in precipitation 2.3 JulAugust: 2.86 in precipitation 2.9 AugSeptember: 5.73 in precipitation 5.7 SepOctober: 7.89 in precipitation, 0.4 in snowfall 7.9 OctNovember: 6.66 in precipitation, 6.2 in snowfall 6.7❄6 NovDecember: 7.88 in precipitation, 15.8 in snowfall 7.9❄16 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Dutch Harbor, AK (within 1 mile); precipitation: Dutch Harbor, AK (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

2 of the 2 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

996858a
Unalaska, AK · 3 mi
995538a
Akutan, AK · 33 mi

Alaska planting zones →

Questions about 99692

What planting zone is ZIP code 99692?

ZIP code 99692 (Dutch Harbor, AK) is in USDA hardiness zone 8b on the 2023 map: the coldest night of an average winter reaches 15 to 20 °F (−9.4 to −6.7 °C).

When is the last frost in Dutch Harbor, AK?

The median last spring frost (32 °F) near 99692 is May 6; after May 22 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Dutch Harbor station.

When is the first frost in Dutch Harbor, AK?

The median first fall frost near 99692 is October 18, giving a median frost-free growing season of 164 days.

When should I plant tomatoes in 99692?

Start tomato seeds indoors around Mar 11 – Mar 25 and set transplants outside around May 13 – May 27, one to three weeks after the median last frost.

How much rain and snow does 99692 get?

About 60.1 inches of precipitation a year and 82 inches of snowfall (NOAA 1991–2020 normals, Dutch Harbor station).

How hot do summers get in Dutch Harbor, AK?

The average high peaks at 59 °F in August, with about 0 days a year at 90 °F or more.

What kind of soil does 99692 have?

The USDA soil survey maps E26-Maritime herbaceous-ashy slopes at the center of ZIP 99692: slightly decomposed plant material, well drained, pH about 6.4 (slightly acidic).

What kind of onions grow in Dutch Harbor, AK?

Long-day onions: the longest day near 99692 is 17 h 07 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 99692 change?

Yes. The 2012 USDA map put 99692 in zone 7b; the 2023 map puts it in zone 8b. The newer map uses 1991–2020 data and more weather stations.