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

Planting zone for 99574 — Cordova, AK

ZIP code 99574 (Cordova, Chugach Census Area County) 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 October 3.

Where ZIP 99574 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 frostOct 3

2012 zone7b

Was 7b on the 2012 map — 2.5 zones 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 Cordova, 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 Cordova, 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 plantsMay 29only 10% chance of frost after

First fall frostOctober 3median — 10% chance by Sep 21

Growing season139 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 30 and returns around October 18.

From the NOAA station Cannery Creek, AK — 7 miles away, elevation 85 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 99574

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 · Aug 8 – Aug 22

GarlicPlant cloves · Sep 19 – Oct 24

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 16) and first fall frost (Oct 3) 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 Cordova, AK.

Soil in Cordova, AK

The soil mapped at the center of ZIP 99574 is E22-maritime subalpine wet meadow-scrub-organic slopes — peat, very poorly drained.

TexturePeattop layer

DrainageVery 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 Subalpine and 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 99574; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Cordova, AK

Summer high62 °Faverage high, July

Winter low20 °Faverage low, January

Hot days0days a year at 90 °F or more

Freezing nights189nights a year at 32 °F or less

Growing degree days422base 50 °F — the season’s usable heat

Longest day19 h 20 mindaylight on June 21

Shortest day5 h 29 mindaylight on December 21

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

Precipitation122 inper year, rain and melted snow

Snowfall151 inper year; 180 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Cannery Creek, AK (7 mi away); precipitation: Cannery Creek, AK (7 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.

Glennallen, AK · 114 mi

Alaska planting zones →

Questions about 99574

What planting zone is ZIP code 99574?

ZIP code 99574 (Cordova, 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 Cordova, AK?

The median last spring frost (32 °F) near 99574 is May 16; after May 29 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Cannery Creek station.

When is the first frost in Cordova, AK?

The median first fall frost near 99574 is October 3, giving a median frost-free growing season of 139 days.

When should I plant tomatoes in 99574?

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 99574 get?

About 122 inches of precipitation a year and 151 inches of snowfall (NOAA 1991–2020 normals, Cannery Creek station).

How hot do summers get in Cordova, AK?

The average high peaks at 62 °F in July, with about 0 days a year at 90 °F or more.

What kind of soil does 99574 have?

The USDA soil survey maps E22-maritime subalpine wet meadow-scrub-organic slopes at the center of ZIP 99574: peat, very poorly drained.

What kind of onions grow in Cordova, AK?

Long-day onions: the longest day near 99574 is 19 h 20 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 99574 change?

Yes. The 2012 USDA map put 99574 in zone 7b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.