Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 99923 — Hyder, AK

ZIP code 99923 (Hyder, Prince of Wales-Hyder County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is May 4 and the first fall frost October 11.

Where ZIP 99923 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.

Zone6b−5 to 0 °F

Coldest night−20.6 to −17.8 °C

Last frostMay 4

First frostOct 11

2012 zone6b

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 6b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Hyder, 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 Hyder, AK

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostMay 4median — 50% chance of a later frost

Safe for tender plantsMay 23only 10% chance of frost after

First fall frostOctober 11median — 10% chance by Oct 1

Growing season157 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 22 and returns around October 25.

From the NOAA station Hyder, AK — 6 miles away, elevation 79 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 99923

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 23 – Apr 6

SpinachSow outdoors · Mar 23 – Apr 13

Broccoli, cabbageStart indoors · Feb 23 – Mar 9

Broccoli, cabbageTransplant · Apr 13 – Apr 27

Onion setsPlant outdoors · Apr 6 – Apr 20

PotatoesPlant outdoors · Apr 13 – Apr 27

LettuceSow outdoors · Apr 6 – Apr 20

Carrots, beetsSow outdoors · Apr 13 – Apr 27

TomatoesStart indoors · Mar 9 – Mar 23

TomatoesTransplant · May 11 – May 25

Peppers, eggplantStart indoors · Feb 23 – Mar 9

Peppers, eggplantTransplant · May 18 – Jun 1

BeansSow outdoors · May 11 – May 25

Sweet cornSow outdoors · May 11 – May 25

Cucumbers, squashSow outdoors · May 11 – May 25

Fall lettuce, spinachSow outdoors · Aug 16 – Aug 30

GarlicPlant cloves · Sep 27 – Nov 1

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 4) and first fall frost (Oct 11) 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 6b in Alaska

286 plants native to Alaska, recorded in Alaska, and rated by the USDA to survive −5 °F or colder — the bottom of zone 6b. Each links to its USDA PLANTS profile.

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 Hyder, AK.

Soil in Hyder, AK

The soil mapped at the center of ZIP 99923 is McGilvery — peat, well drained.

TexturePeattop layer

pH3.5strongly 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: Talus slopes-McGilvery complex, 60 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 99923; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Hyder, AK

Summer high68 °Faverage high, July

Winter low22 °Faverage low, January

Hot days1days a year at 90 °F or more

Freezing nights152nights a year at 32 °F or less

Growing degree days947base 50 °F — the season’s usable heat

Longest day17 h 37 mindaylight on June 21

Shortest day6 h 57 mindaylight on December 21

Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)

Precipitation92.5 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

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

Nearby ZIP codes

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

999017b

Ketchikan, AK · 57 mi

999288a

Ward Cove, AK · 76 mi

999268a

Metlakatla, AK · 82 mi

Alaska planting zones →

Questions about 99923

What planting zone is ZIP code 99923?

ZIP code 99923 (Hyder, AK) is in USDA hardiness zone 6b on the 2023 map: the coldest night of an average winter reaches −5 to 0 °F (−20.6 to −17.8 °C).

When is the last frost in Hyder, AK?

The median last spring frost (32 °F) near 99923 is May 4; after May 23 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Hyder station.

When is the first frost in Hyder, AK?

The median first fall frost near 99923 is October 11, giving a median frost-free growing season of 157 days.

When should I plant tomatoes in 99923?

Start tomato seeds indoors around Mar 9 – Mar 23 and set transplants outside around May 11 – May 25, one to three weeks after the median last frost.

How much rain and snow does 99923 get?

About 92.5 inches of precipitation a year (NOAA 1991–2020 normals, Hyder station).

How hot do summers get in Hyder, AK?

The average high peaks at 68 °F in July, with about 1 days a year at 90 °F or more.

What kind of soil does 99923 have?

The USDA soil survey maps McGilvery at the center of ZIP 99923: peat, well drained, pH about 3.5 (strongly acidic).

What kind of onions grow in Hyder, AK?

Long-day onions: the longest day near 99923 is 17 h 37 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).