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

Planting zone for 99567 — Chugiak, AK

ZIP code 99567 (Chugiak, Anchorage Municipality) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 16 and the first fall frost September 20.

Where ZIP 99567 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 frostMay 16

First frostSep 20

2012 zone4b

Was 4b 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 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Chugiak, 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 Chugiak, AK

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 16median — 50% chance of a later frost

Safe for tender plantsJune 9only 10% chance of frost after

First fall frostSeptember 20median — 10% chance by Sep 4

Growing season125 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 1 and returns around October 1.

From the NOAA station Eagle Rvr Nature Center, AK — 9 miles away, elevation 522 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 99567

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 4 – Apr 18

SpinachSow outdoors · Apr 4 – Apr 25

Broccoli, cabbageStart indoors · Mar 7 – Mar 21

Broccoli, cabbageTransplant · Apr 25 – May 9

Onion setsPlant outdoors · Apr 18 – May 2

PotatoesPlant outdoors · Apr 25 – May 9

LettuceSow outdoors · Apr 18 – May 2

Carrots, beetsSow outdoors · Apr 25 – May 9

TomatoesStart indoors · Mar 21 – Apr 4

TomatoesTransplant · May 23 – Jun 6

Peppers, eggplantStart indoors · Mar 7 – Mar 21

Peppers, eggplantTransplant · May 30 – Jun 13

BeansSow outdoors · May 23 – Jun 6

Sweet cornSow outdoors · May 23 – Jun 6

Cucumbers, squashSow outdoors · May 23 – Jun 6

Fall lettuce, spinachSow outdoors · Jul 26 – Aug 9

GarlicPlant cloves · Sep 6 – Oct 11

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 16) and first fall frost (Sep 20) 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.

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 Chugiak, AK.

Soil in Chugiak, AK

The soil mapped at the center of ZIP 99567 is Nakochna — moderately decomposed plant material, well drained.

TextureModerately decomposed plant materialtop layer

pH4.4strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter55%high

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Nakochna-Rock outcrop association, 20 to 85 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 99567; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Chugiak, AK

Summer high67 °Faverage high, July

Winter low6 °Faverage low, January

Hot days0days a year at 90 °F or more

Freezing nights204nights a year at 32 °F or less

Growing degree days587base 50 °F — the season’s usable heat

Longest day19 h 25 mindaylight on June 21

Shortest day5 h 25 mindaylight on December 21

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

Precipitation19.2 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: Eagle Rvr Nature Center, AK (9 mi away); precipitation: Moraine, AK (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

995775a

Eagle River, AK · 12 mi

995045a

Anchorage, AK · 21 mi

Anchorage, AK · 24 mi

995875b

Girdwood, AK · 24 mi

Alaska planting zones →

Questions about 99567

What planting zone is ZIP code 99567?

ZIP code 99567 (Chugiak, 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 Chugiak, AK?

The median last spring frost (32 °F) near 99567 is May 16; after June 9 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Eagle Rvr Nature Center station.

When is the first frost in Chugiak, AK?

The median first fall frost near 99567 is September 20, giving a median frost-free growing season of 125 days.

When should I plant tomatoes in 99567?

Start tomato seeds indoors around Mar 21 – Apr 4 and set transplants outside around May 23 – Jun 6, one to three weeks after the median last frost.

How much rain and snow does 99567 get?

About 19.2 inches of precipitation a year (NOAA 1991–2020 normals, Moraine station).

How hot do summers get in Chugiak, AK?

The average high peaks at 67 °F in July, with about 0 days a year at 90 °F or more.

What kind of soil does 99567 have?

The USDA soil survey maps Nakochna at the center of ZIP 99567: moderately decomposed plant material, well drained, pH about 4.4 (strongly acidic).

What kind of onions grow in Chugiak, AK?

Long-day onions: the longest day near 99567 is 19 h 25 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 99567 change?

Yes. The 2012 USDA map put 99567 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.