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

Planting zone for 99605 — Hope, AK

ZIP code 99605 (Hope, Kenai Peninsula County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is May 18 and the first fall frost September 24.

Where ZIP 99605 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.

Zone5b−15 to −10 °F
Coldest night−26.1 to −23.3 °C
Last frostMay 18
First frostSep 24
2012 zone5a

Was 5a 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 5b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Hope, 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 Hope, AK

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 18median — 50% chance of a later frost
Safe for tender plantsMay 28only 10% chance of frost after
First fall frostSeptember 24median — 10% chance by Sep 12
Growing season127 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 5 and returns around October 5.

From the NOAA station Hope, AK — 6 miles away, elevation 180 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 99605

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 6 – Apr 20
SpinachSow outdoors · Apr 6 – Apr 27
Broccoli, cabbageStart indoors · Mar 9 – Mar 23
Broccoli, cabbageTransplant · Apr 27 – May 11
Onion setsPlant outdoors · Apr 20 – May 4
PotatoesPlant outdoors · Apr 27 – May 11
LettuceSow outdoors · Apr 20 – May 4
Carrots, beetsSow outdoors · Apr 27 – May 11
TomatoesStart indoors · Mar 23 – Apr 6
TomatoesTransplant · May 25 – Jun 8
Peppers, eggplantStart indoors · Mar 9 – Mar 23
Peppers, eggplantTransplant · Jun 1 – Jun 15
BeansSow outdoors · May 25 – Jun 8
Sweet cornSow outdoors · May 25 – Jun 8
Cucumbers, squashSow outdoors · May 25 – Jun 8
Fall lettuce, spinachSow outdoors · Jul 30 – Aug 13
GarlicPlant cloves · Sep 10 – Oct 15
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 18) and first fall frost (Sep 24) 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 5b in Alaska

282 plants native to Alaska, recorded in Alaska, and rated by the USDA to survive −15 °F or colder — the bottom of zone 5b. 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 47

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 122

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 88

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 Hope, AK.

Soil in Hope, AK

The soil mapped at the center of ZIP 99605 is E23-boreal alpine scrub-gravelly colluvial slopes — moderately decomposed plant material, well drained.

TextureModerately decomposed plant materialtop layer
pH5.0strongly 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: Cook Inlet Mountains-Boreal Alpine-Mountains.

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 99605; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Hope, AK

Summer high66 °Faverage high, July
Winter low10 °Faverage low, January
Hot days0days a year at 90 °F or more
Freezing nights212nights a year at 32 °F or less
Growing degree days554base 50 °F — the season’s usable heat
Longest day19 h 13 mindaylight on June 21
Shortest day5 h 34 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation66.3 inper year, rain and melted snow

Average high and low, by month

0°10°20°30°40°50°60°70°80°32 °FJanuary: average high 25 °F, low 10 °F 25°10° JanFebruary: average high 30 °F, low 15 °F 30°15° FebMarch: average high 34 °F, low 16 °F 34°16° MarApril: average high 45 °F, low 27 °F 45°27° AprMay: average high 56 °F, low 35 °F 56°35° MayJune: average high 63 °F, low 44 °F 63°44° JunJuly: average high 66 °F, low 49 °F 66°49° JulAugust: average high 63 °F, low 47 °F 63°47° AugSeptember: average high 55 °F, low 39 °F 55°39° SepOctober: average high 42 °F, low 28 °F 42°28° OctNovember: average high 29 °F, low 17 °F 29°17° NovDecember: average high 27 °F, low 14 °F 27°14° Dec

Precipitation by month inches

0″2″4″6″8″January: 6.26 in precipitation 6.3 JanFebruary: 5.96 in precipitation 6.0 FebMarch: 5.52 in precipitation 5.5 MarApril: 5.73 in precipitation 5.7 AprMay: 3.53 in precipitation 3.5 MayJune: 2.19 in precipitation 2.2 JunJuly: 2.37 in precipitation 2.4 JulAugust: 4.42 in precipitation 4.4 AugSeptember: 8.16 in precipitation 8.2 SepOctober: 7.21 in precipitation 7.2 OctNovember: 6.91 in precipitation 6.9 NovDecember: 8.04 in precipitation 8.0 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Hope, AK (6 mi away); precipitation: Turnagain Pass, AK (12 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

995405b
Indian, AK · 11 mi
995165b
Anchorage, AK · 17 mi
995115a
Anchorage, AK · 18 mi
995075a
Anchorage, AK · 18 mi
996315a
Moose Pass, AK · 20 mi
995875b
Girdwood, AK · 21 mi
995775a
Eagle River, AK · 22 mi
995155a
Anchorage, AK · 22 mi

Alaska planting zones →

Questions about 99605

What planting zone is ZIP code 99605?

ZIP code 99605 (Hope, AK) is in USDA hardiness zone 5b on the 2023 map: the coldest night of an average winter reaches −15 to −10 °F (−26.1 to −23.3 °C).

When is the last frost in Hope, AK?

The median last spring frost (32 °F) near 99605 is May 18; after May 28 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Hope station.

When is the first frost in Hope, AK?

The median first fall frost near 99605 is September 24, giving a median frost-free growing season of 127 days.

When should I plant tomatoes in 99605?

Start tomato seeds indoors around Mar 23 – Apr 6 and set transplants outside around May 25 – Jun 8, one to three weeks after the median last frost.

How much rain and snow does 99605 get?

About 66.3 inches of precipitation a year (NOAA 1991–2020 normals, Turnagain Pass station).

How hot do summers get in Hope, AK?

The average high peaks at 66 °F in July, with about 0 days a year at 90 °F or more.

What kind of soil does 99605 have?

The USDA soil survey maps E23-boreal alpine scrub-gravelly colluvial slopes at the center of ZIP 99605: moderately decomposed plant material, well drained, pH about 5.0 (strongly acidic).

What kind of onions grow in Hope, AK?

Long-day onions: the longest day near 99605 is 19 h 13 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 99605 change?

Yes. The 2012 USDA map put 99605 in zone 5a; the 2023 map puts it in zone 5b. The newer map uses 1991–2020 data and more weather stations.