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

Planting zone for 99836 — Port Alexander, AK

ZIP code 99836 (Port Alexander, Prince of Wales-Hyder County) is in USDA zone 8a: the coldest winter night averages 10 to 15 °F. The median last spring frost is April 18 and the first fall frost November 5.

Where ZIP 99836 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.

Zone8a10 to 15 °F
Coldest night−12.2 to −9.4 °C
Last frostApr 18
First frostNov 5
2012 zone8a

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 8a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Port Alexander, 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 Port Alexander, AK

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 18median — 50% chance of a later frost
Safe for tender plantsMay 5only 10% chance of frost after
First fall frostNovember 5median — 10% chance by Oct 16
Growing season198 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 26 and returns around November 24.

From the NOAA station Port Alexander, AK — within 1 mile, elevation 13 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 99836

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 7 – Mar 21
SpinachSow outdoors · Mar 7 – Mar 28
Broccoli, cabbageStart indoors · Feb 7 – Feb 21
Broccoli, cabbageTransplant · Mar 28 – Apr 11
Onion setsPlant outdoors · Mar 21 – Apr 4
PotatoesPlant outdoors · Mar 28 – Apr 11
LettuceSow outdoors · Mar 21 – Apr 4
Carrots, beetsSow outdoors · Mar 28 – Apr 11
TomatoesStart indoors · Feb 21 – Mar 7
TomatoesTransplant · Apr 25 – May 9
Peppers, eggplantStart indoors · Feb 7 – Feb 21
Peppers, eggplantTransplant · May 2 – May 16
BeansSow outdoors · Apr 25 – May 9
Sweet cornSow outdoors · Apr 25 – May 9
Cucumbers, squashSow outdoors · Apr 25 – May 9
Fall lettuce, spinachSow outdoors · Sep 10 – Sep 24
GarlicPlant cloves · Oct 22 – Nov 26
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 18) and first fall frost (Nov 5) 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 8a in Alaska

292 plants native to Alaska, recorded in Alaska, and rated by the USDA to survive 10 °F or colder — the bottom of zone 8a. 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 51

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 Port Alexander, AK.

Soil in Port Alexander, AK

The soil mapped at the center of ZIP 99836 is Lithic Cryosaprists — peat, very poorly drained.

TexturePeattop layer
pH4.0strongly acidic; most vegetables like 6.0–7.0
DrainageVery poorly drainedconsider raised beds
Organic matter92.5%high
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Lithic Cryosaprists, rolling hills, 36 to 55 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 99836; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Port Alexander, AK

Summer high64 °Faverage high, July
Winter low32 °Faverage low, January
Hot days0days a year at 90 °F or more
Freezing nights68nights a year at 32 °F or less
Growing degree days726base 50 °F — the season’s usable heat
Longest day17 h 41 mindaylight on June 21
Shortest day6 h 53 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation162 inper year, rain and melted snow
Snowfall56 inper year; 39 days with snow on the ground

Average high and low, by month

20°30°40°50°60°70°32 °FJanuary: average high 40 °F, low 32 °F 40°32° JanFebruary: average high 41 °F, low 33 °F 41°33° FebMarch: average high 43 °F, low 33 °F 43°33° MarApril: average high 50 °F, low 37 °F 50°37° AprMay: average high 57 °F, low 42 °F 57°42° MayJune: average high 61 °F, low 47 °F 61°47° JunJuly: average high 64 °F, low 50 °F 64°50° JulAugust: average high 64 °F, low 50 °F 64°50° AugSeptember: average high 58 °F, low 47 °F 58°47° SepOctober: average high 51 °F, low 42 °F 51°42° OctNovember: average high 44 °F, low 36 °F 44°36° NovDecember: average high 41 °F, low 33 °F 41°33° Dec

Precipitation by month inches · ❄ = snowfall

0″2″4″6″8″10″12″14″16″18″20″January: 16.25 in precipitation, 12.3 in snowfall 16.3❄12 JanFebruary: 11.72 in precipitation, 12 in snowfall 11.7❄12 FebMarch: 11.05 in precipitation, 11.9 in snowfall 11.1❄12 MarApril: 8.64 in precipitation, 1.2 in snowfall 8.6❄1 AprMay: 7.86 in precipitation, 0.1 in snowfall 7.9 MayJune: 6.65 in precipitation 6.7 JunJuly: 9.03 in precipitation 9.0 JulAugust: 13.94 in precipitation 13.9 AugSeptember: 19.34 in precipitation 19.3 SepOctober: 19.85 in precipitation, 0.3 in snowfall 19.9 OctNovember: 18.12 in precipitation, 4.1 in snowfall 18.1❄4 NovDecember: 19.58 in precipitation, 14.1 in snowfall 19.6❄14 Dec

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

Nearby ZIP codes

4 of the 6 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

999278a
Point Baker, AK · 41 mi
998307b
Kake, AK · 42 mi
998357b
Sitka, AK · 51 mi
998337b
Petersburg, AK · 69 mi
998207a
Angoon, AK · 79 mi
999228a
Hydaburg, AK · 90 mi

Alaska planting zones →

Questions about 99836

What planting zone is ZIP code 99836?

ZIP code 99836 (Port Alexander, AK) is in USDA hardiness zone 8a on the 2023 map: the coldest night of an average winter reaches 10 to 15 °F (−12.2 to −9.4 °C).

When is the last frost in Port Alexander, AK?

The median last spring frost (32 °F) near 99836 is April 18; after May 5 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Port Alexander station.

When is the first frost in Port Alexander, AK?

The median first fall frost near 99836 is November 5, giving a median frost-free growing season of 198 days.

When should I plant tomatoes in 99836?

Start tomato seeds indoors around Feb 21 – Mar 7 and set transplants outside around Apr 25 – May 9, one to three weeks after the median last frost.

How much rain and snow does 99836 get?

About 162 inches of precipitation a year and 56 inches of snowfall (NOAA 1991–2020 normals, Port Alexander station).

How hot do summers get in Port Alexander, AK?

The average high peaks at 64 °F in July, with about 0 days a year at 90 °F or more.

What kind of soil does 99836 have?

The USDA soil survey maps Lithic Cryosaprists at the center of ZIP 99836: peat, very poorly drained, pH about 4.0 (strongly acidic).

What kind of onions grow in Port Alexander, AK?

Long-day onions: the longest day near 99836 is 17 h 41 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).