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

Planting zone for 99676 — Talkeetna, AK

ZIP code 99676 (Talkeetna, Matanuska-Susitna Borough) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is May 16 and the first fall frost September 16.

Where ZIP 99676 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.

Zone4b−25 to −20 °F

Coldest night−31.7 to −28.9 °C

Last frostMay 16

First frostSep 16

2012 zone3b

Was 3b on the 2012 map — a full zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 4b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Talkeetna, 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 Talkeetna, 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 28only 10% chance of frost after

First fall frostSeptember 16median — 10% chance by Sep 1

Growing season122 daysfrost-free, median

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

From the NOAA station Talkeetna Airport, AK — 24 miles away, elevation 351 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 99676

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 22 – Aug 5

GarlicPlant cloves · Sep 2 – Oct 7

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 16) and first fall frost (Sep 16) 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 4b in Alaska

260 plants native to Alaska, recorded in Alaska, and rated by the USDA to survive −25 °F or colder — the bottom of zone 4b. 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 Talkeetna, AK.

Soil in Talkeetna, AK

The soil mapped at the center of ZIP 99676 is E23-boreal subalpine scrub/meadow mosaic-silty acid slopes — slightly decomposed plant material, well drained.

TextureSlightly 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 Subalpine and Alpine-Rounded Mountains, Acid.

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 99676; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Talkeetna, AK

Summer high67 °Faverage high, July

Winter low0 °Faverage low, January

Hot days0days a year at 90 °F or more

Freezing nights246nights a year at 32 °F or less

Growing degree days297base 50 °F — the season’s usable heat

Longest day20 h 03 mindaylight on June 21

Shortest day4 h 54 mindaylight on December 21

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

Precipitation31.5 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: Chulitna Rvr, AK (20 mi away); precipitation: Chulitna Rvr, AK (20 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

996834b

Trapper Creek, AK · 28 mi

Alaska planting zones →

Questions about 99676

What planting zone is ZIP code 99676?

ZIP code 99676 (Talkeetna, AK) is in USDA hardiness zone 4b on the 2023 map: the coldest night of an average winter reaches −25 to −20 °F (−31.7 to −28.9 °C).

When is the last frost in Talkeetna, AK?

The median last spring frost (32 °F) near 99676 is May 16; after May 28 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Talkeetna Airport station.

When is the first frost in Talkeetna, AK?

The median first fall frost near 99676 is September 16, giving a median frost-free growing season of 122 days.

When should I plant tomatoes in 99676?

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 99676 get?

About 31.5 inches of precipitation a year (NOAA 1991–2020 normals, Chulitna Rvr station).

How hot do summers get in Talkeetna, 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 99676 have?

The USDA soil survey maps E23-boreal subalpine scrub/meadow mosaic-silty acid slopes at the center of ZIP 99676: slightly decomposed plant material, well drained, pH about 5.0 (strongly acidic).

What kind of onions grow in Talkeetna, AK?

Long-day onions: the longest day near 99676 is 20 h 03 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 99676 change?

Yes. The 2012 USDA map put 99676 in zone 3b; the 2023 map puts it in zone 4b. The newer map uses 1991–2020 data and more weather stations.