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

Planting zone for 99925 — Klawock, AK

ZIP code 99925 (Klawock, Prince of Wales-Hyder County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is April 29 and the first fall frost October 16.

Where ZIP 99925 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.

Zone7b5 to 10 °F
Coldest night−15 to −12.2 °C
Last frostApr 29
First frostOct 16
2012 zone7b

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 7b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Klawock, 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 Klawock, AK

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 29median — 50% chance of a later frost
Safe for tender plantsMay 14only 10% chance of frost after
First fall frostOctober 16median — 10% chance by Oct 1
Growing season169 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 9 and returns around November 5.

From the NOAA station Klawock Airport, AK — 6 miles away, 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 99925

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 18 – Apr 1
SpinachSow outdoors · Mar 18 – Apr 8
Broccoli, cabbageStart indoors · Feb 18 – Mar 4
Broccoli, cabbageTransplant · Apr 8 – Apr 22
Onion setsPlant outdoors · Apr 1 – Apr 15
PotatoesPlant outdoors · Apr 8 – Apr 22
LettuceSow outdoors · Apr 1 – Apr 15
Carrots, beetsSow outdoors · Apr 8 – Apr 22
TomatoesStart indoors · Mar 4 – Mar 18
TomatoesTransplant · May 6 – May 20
Peppers, eggplantStart indoors · Feb 18 – Mar 4
Peppers, eggplantTransplant · May 13 – May 27
BeansSow outdoors · May 6 – May 20
Sweet cornSow outdoors · May 6 – May 20
Cucumbers, squashSow outdoors · May 6 – May 20
Fall lettuce, spinachSow outdoors · Aug 21 – Sep 4
GarlicPlant cloves · Oct 2 – Nov 6
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 29) and first fall frost (Oct 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 7b in Alaska

289 plants native to Alaska, recorded in Alaska, and rated by the USDA to survive 5 °F or colder — the bottom of zone 7b. 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 Klawock, AK.

Soil in Klawock, AK

The soil mapped at the center of ZIP 99925 is Tolstoi — slightly decomposed plant material, well drained.

TextureSlightly decomposed plant materialtop layer
pH4.2strongly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter80%high
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Tolstoi very fine sandy loam, 5 to 100 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 99925; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Klawock, AK

Summer high64 °Faverage high, August
Winter low30 °Faverage low, February
Hot days0days a year at 90 °F or more
Freezing nights94nights a year at 32 °F or less
Growing degree days728base 50 °F — the season’s usable heat
Longest day17 h 30 mindaylight on June 21
Shortest day7 h 03 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation89.2 inper year, rain and melted snow

Average high and low, by month

20°30°40°50°60°70°32 °FJanuary: average high 40 °F, low 31 °F 40°31° JanFebruary: average high 41 °F, low 30 °F 41°30° FebMarch: average high 44 °F, low 31 °F 44°31° MarApril: average high 51 °F, low 35 °F 51°35° AprMay: average high 57 °F, low 41 °F 57°41° MayJune: average high 61 °F, low 46 °F 61°46° JunJuly: average high 63 °F, low 51 °F 63°51° JulAugust: average high 64 °F, low 51 °F 64°51° AugSeptember: average high 60 °F, low 47 °F 60°47° SepOctober: average high 52 °F, low 40 °F 52°40° OctNovember: average high 44 °F, low 34 °F 44°34° NovDecember: average high 40 °F, low 31 °F 40°31° Dec

Precipitation by month inches

0″2″4″6″8″10″12″January: 8.65 in precipitation 8.7 JanFebruary: 6.33 in precipitation 6.3 FebMarch: 6.82 in precipitation 6.8 MarApril: 5.51 in precipitation 5.5 AprMay: 4.10 in precipitation 4.1 MayJune: 3.41 in precipitation 3.4 JunJuly: 4.27 in precipitation 4.3 JulAugust: 6.79 in precipitation 6.8 AugSeptember: 10.72 in precipitation 10.7 SepOctober: 12.33 in precipitation 12.3 OctNovember: 10.17 in precipitation 10.2 NovDecember: 10.10 in precipitation 10.1 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Klawock Airport, AK (6 mi away); precipitation: Klawock Airport, AK (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

999217b
Craig, AK · 10 mi
999228a
Hydaburg, AK · 17 mi
999197b
Thorne Bay, AK · 19 mi
999188a
Coffman Cove, AK · 27 mi
999037b
Meyers Chuck, AK · 35 mi
999288a
Ward Cove, AK · 51 mi
999278a
Point Baker, AK · 60 mi
999297b
Wrangell, AK · 61 mi

Alaska planting zones →

Questions about 99925

What planting zone is ZIP code 99925?

ZIP code 99925 (Klawock, AK) is in USDA hardiness zone 7b on the 2023 map: the coldest night of an average winter reaches 5 to 10 °F (−15 to −12.2 °C).

When is the last frost in Klawock, AK?

The median last spring frost (32 °F) near 99925 is April 29; after May 14 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Klawock Airport station.

When is the first frost in Klawock, AK?

The median first fall frost near 99925 is October 16, giving a median frost-free growing season of 169 days.

When should I plant tomatoes in 99925?

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

How much rain and snow does 99925 get?

About 89.2 inches of precipitation a year (NOAA 1991–2020 normals, Klawock Airport station).

How hot do summers get in Klawock, AK?

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

What kind of soil does 99925 have?

The USDA soil survey maps Tolstoi at the center of ZIP 99925: slightly decomposed plant material, well drained, pH about 4.2 (strongly acidic).

What kind of onions grow in Klawock, AK?

Long-day onions: the longest day near 99925 is 17 h 30 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).