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

Planting zone for 99550 — Port Lions, AK

ZIP code 99550 (Port Lions, Kodiak Island County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is May 9 and the first fall frost October 4.

Where ZIP 99550 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 9
First frostOct 4
2012 zone7a

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 7a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Port Lions, 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 Lions, AK

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 9median — 50% chance of a later frost
Safe for tender plantsMay 23only 10% chance of frost after
First fall frostOctober 4median — 10% chance by Sep 22
Growing season148 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 18 and returns around October 19.

From the NOAA station Ouzinkie, AK — 14 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 99550

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 28 – Apr 11
SpinachSow outdoors · Mar 28 – Apr 18
Broccoli, cabbageStart indoors · Feb 28 – Mar 14
Broccoli, cabbageTransplant · Apr 18 – May 2
Onion setsPlant outdoors · Apr 11 – Apr 25
PotatoesPlant outdoors · Apr 18 – May 2
LettuceSow outdoors · Apr 11 – Apr 25
Carrots, beetsSow outdoors · Apr 18 – May 2
TomatoesStart indoors · Mar 14 – Mar 28
TomatoesTransplant · May 16 – May 30
Peppers, eggplantStart indoors · Feb 28 – Mar 14
Peppers, eggplantTransplant · May 23 – Jun 6
BeansSow outdoors · May 16 – May 30
Sweet cornSow outdoors · May 16 – May 30
Cucumbers, squashSow outdoors · May 16 – May 30
Fall lettuce, spinachSow outdoors · Aug 9 – Aug 23
GarlicPlant cloves · Sep 20 – Oct 25
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 9) and first fall frost (Oct 4) 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 Port Lions, AK.

Soil in Port Lions, AK

The soil mapped at the center of ZIP 99550 is Kodiak — moderately decomposed plant material, well drained.

TextureModerately decomposed plant materialtop layer
pH5.2strongly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter75%high
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Kodiak-Marka-Afognak complex, 5 to 30 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 99550; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Port Lions, AK

Summer high61 °Faverage high, August
Winter low26 °Faverage low, January
Hot days0days a year at 90 °F or more
Freezing nights148nights a year at 32 °F or less
Growing degree days339base 50 °F — the season’s usable heat
Longest day18 h 08 mindaylight on June 21
Shortest day6 h 29 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation102.5 inper year, rain and melted snow

Average high and low, by month

20°30°40°50°60°70°32 °FJanuary: average high 35 °F, low 26 °F 35°26° JanFebruary: average high 35 °F, low 27 °F 35°27° FebMarch: average high 37 °F, low 26 °F 37°26° MarApril: average high 43 °F, low 32 °F 43°32° AprMay: average high 50 °F, low 38 °F 50°38° MayJune: average high 55 °F, low 44 °F 55°44° JunJuly: average high 60 °F, low 48 °F 60°48° JulAugust: average high 61 °F, low 48 °F 61°48° AugSeptember: average high 55 °F, low 43 °F 55°43° SepOctober: average high 46 °F, low 35 °F 46°35° OctNovember: average high 39 °F, low 30 °F 39°30° NovDecember: average high 36 °F, low 26 °F 36°26° Dec

Precipitation by month inches

0″2″4″6″8″10″12″January: 11.17 in precipitation 11.2 JanFebruary: 8.31 in precipitation 8.3 FebMarch: 5.46 in precipitation 5.5 MarApril: 7.83 in precipitation 7.8 AprMay: 7.81 in precipitation 7.8 MayJune: 7.19 in precipitation 7.2 JunJuly: 6.28 in precipitation 6.3 JulAugust: 6.91 in precipitation 6.9 AugSeptember: 9.69 in precipitation 9.7 SepOctober: 11.49 in precipitation 11.5 OctNovember: 9.67 in precipitation 9.7 NovDecember: 10.70 in precipitation 10.7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Ouzinkie, AK (14 mi away); precipitation: Monashka Creek Dam, AK (15 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

996197b
Kodiak, AK · 17 mi
996977b
Kodiak, AK · 17 mi
996447b
Ouzinkie, AK · 18 mi
996157a
Kodiak, AK · 23 mi
996247b
Larsen Bay, AK · 45 mi
996437b
Old Harbor, AK · 48 mi
996087a
Karluk, AK · 59 mi
996636b
Seldovia, AK · 115 mi

Alaska planting zones →

Questions about 99550

What planting zone is ZIP code 99550?

ZIP code 99550 (Port Lions, 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 Port Lions, AK?

The median last spring frost (32 °F) near 99550 is May 9; after May 23 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Ouzinkie station.

When is the first frost in Port Lions, AK?

The median first fall frost near 99550 is October 4, giving a median frost-free growing season of 148 days.

When should I plant tomatoes in 99550?

Start tomato seeds indoors around Mar 14 – Mar 28 and set transplants outside around May 16 – May 30, one to three weeks after the median last frost.

How much rain and snow does 99550 get?

About 102.5 inches of precipitation a year (NOAA 1991–2020 normals, Monashka Creek Dam station).

How hot do summers get in Port Lions, AK?

The average high peaks at 61 °F in August, with about 0 days a year at 90 °F or more.

What kind of soil does 99550 have?

The USDA soil survey maps Kodiak at the center of ZIP 99550: moderately decomposed plant material, well drained, pH about 5.2 (strongly acidic).

What kind of onions grow in Port Lions, AK?

Long-day onions: the longest day near 99550 is 18 h 08 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).