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

Planting zone for 99686 — Valdez, AK

ZIP code 99686 (Valdez, Chugach Census Area County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is April 30 and the first fall frost October 2.

Where ZIP 99686 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.

Zone5a−20 to −15 °F
Coldest night−28.9 to −26.1 °C
Last frostApr 30
First frostOct 2
2012 zone6a

Was 6a on the 2012 map — a full zone colder now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Valdez, 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 Valdez, AK

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 30median — 50% chance of a later frost
Safe for tender plantsMay 10only 10% chance of frost after
First fall frostOctober 2median — 10% chance by Sep 20
Growing season157 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 14 and returns around October 20.

From the NOAA station Valdez WSO, AK — 8 miles away, elevation 95 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 99686

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 19 – Apr 2
SpinachSow outdoors · Mar 19 – Apr 9
Broccoli, cabbageStart indoors · Feb 19 – Mar 5
Broccoli, cabbageTransplant · Apr 9 – Apr 23
Onion setsPlant outdoors · Apr 2 – Apr 16
PotatoesPlant outdoors · Apr 9 – Apr 23
LettuceSow outdoors · Apr 2 – Apr 16
Carrots, beetsSow outdoors · Apr 9 – Apr 23
TomatoesStart indoors · Mar 5 – Mar 19
TomatoesTransplant · May 7 – May 21
Peppers, eggplantStart indoors · Feb 19 – Mar 5
Peppers, eggplantTransplant · May 14 – May 28
BeansSow outdoors · May 7 – May 21
Sweet cornSow outdoors · May 7 – May 21
Cucumbers, squashSow outdoors · May 7 – May 21
Fall lettuce, spinachSow outdoors · Aug 7 – Aug 21
GarlicPlant cloves · Sep 18 – Oct 23
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 30) and first fall frost (Oct 2) 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 5a in Alaska

275 plants native to Alaska, recorded in Alaska, and rated by the USDA to survive −20 °F or colder — the bottom of zone 5a. Each links to its USDA PLANTS profile.

Trees 14

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 °FPacific silver fir165 ft · blooms late spring · low shade tolerance · to −28 °Fpaper birch70 ft · blooms mid spring · high shade tolerance · to −62 °F

Shrubs 46

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 119

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 87

Alaska 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 °Fbeaked sedge4 ft · blooms late 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 Valdez, AK.

Soil in Valdez, AK

The soil mapped at the center of ZIP 99686 is E22-maritime alpine scrub-gravelly colluvial slopes, shallow — slightly decomposed plant material, somewhat poorly drained.

TextureSlightly decomposed plant materialtop layer
DrainageSomewhat poorly drainedconsider raised beds
Organic matter75%high
Hydrologic groupB/Dmoderate when drained; wet otherwise
Farmland classNot prime farmlandUSDA classification

Map unit: Southern Alaska Coastal Mountains-Maritime Alpine-Barren 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 99686; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Valdez, AK

Summer high64 °Faverage high, July
Winter low19 °Faverage low, January
Hot days0days a year at 90 °F or more
Freezing nights174nights a year at 32 °F or less
Growing degree days537base 50 °F — the season’s usable heat
Longest day19 h 18 mindaylight on June 21
Shortest day5 h 31 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation78.3 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°32 °FJanuary: average high 29 °F, low 19 °F 29°19° JanFebruary: average high 32 °F, low 21 °F 32°21° FebMarch: average high 37 °F, low 23 °F 37°23° MarApril: average high 46 °F, low 32 °F 46°32° AprMay: average high 56 °F, low 40 °F 56°40° MayJune: average high 63 °F, low 46 °F 63°46° JunJuly: average high 64 °F, low 49 °F 64°49° JulAugust: average high 62 °F, low 47 °F 62°47° AugSeptember: average high 55 °F, low 42 °F 55°42° SepOctober: average high 45 °F, low 34 °F 45°34° OctNovember: average high 34 °F, low 25 °F 34°25° NovDecember: average high 31 °F, low 22 °F 31°22° Dec

Precipitation by month inches

0″2″4″6″8″10″January: 8.55 in precipitation 8.6 JanFebruary: 7.09 in precipitation 7.1 FebMarch: 4.46 in precipitation 4.5 MarApril: 4.40 in precipitation 4.4 AprMay: 3.43 in precipitation 3.4 MayJune: 2.65 in precipitation 2.6 JunJuly: 3.77 in precipitation 3.8 JulAugust: 7.96 in precipitation 8.0 AugSeptember: 9.16 in precipitation 9.2 SepOctober: 10.05 in precipitation 10.1 OctNovember: 8.09 in precipitation 8.1 NovDecember: 8.65 in precipitation 8.7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Valdez WSO, AK (8 mi away); precipitation: Sugarloaf Mtn, AK (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

996778a
Tatitlek, AK · 19 mi
995734b
Copper Center, AK · 40 mi
995745a
Cordova, AK · 48 mi
995882b
Glennallen, AK · 116 mi

Alaska planting zones →

Questions about 99686

What planting zone is ZIP code 99686?

ZIP code 99686 (Valdez, AK) is in USDA hardiness zone 5a on the 2023 map: the coldest night of an average winter reaches −20 to −15 °F (−28.9 to −26.1 °C).

When is the last frost in Valdez, AK?

The median last spring frost (32 °F) near 99686 is April 30; after May 10 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Valdez WSO station.

When is the first frost in Valdez, AK?

The median first fall frost near 99686 is October 2, giving a median frost-free growing season of 157 days.

When should I plant tomatoes in 99686?

Start tomato seeds indoors around Mar 5 – Mar 19 and set transplants outside around May 7 – May 21, one to three weeks after the median last frost.

How much rain and snow does 99686 get?

About 78.3 inches of precipitation a year (NOAA 1991–2020 normals, Sugarloaf Mtn station).

How hot do summers get in Valdez, 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 99686 have?

The USDA soil survey maps E22-maritime alpine scrub-gravelly colluvial slopes, shallow at the center of ZIP 99686: slightly decomposed plant material, somewhat poorly drained.

What kind of onions grow in Valdez, AK?

Long-day onions: the longest day near 99686 is 19 h 18 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 99686 change?

Yes. The 2012 USDA map put 99686 in zone 6a; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.