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

Planting zone for 99677 — Tatitlek, AK

ZIP code 99677 (Tatitlek, Chugach Census Area County) is in USDA zone 8a: the coldest winter night averages 10 to 15 °F. The median last spring frost is May 14 and the first fall frost September 22.

Where ZIP 99677 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.

Zone8a10 to 15 °F

Coldest night−12.2 to −9.4 °C

Last frostMay 14

First frostSep 22

2012 zone6b

Was 6b on the 2012 map — 1.5 zones warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 8a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Tatitlek, 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 Tatitlek, AK

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 14median — 50% chance of a later frost

Safe for tender plantsMay 26only 10% chance of frost after

First fall frostSeptember 22median — 10% chance by Sep 6

Growing season129 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 30 and returns around October 4.

From the NOAA station Valdez, AK — 19 miles away, elevation 62 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 99677

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 2 – Apr 16

SpinachSow outdoors · Apr 2 – Apr 23

Broccoli, cabbageStart indoors · Mar 5 – Mar 19

Broccoli, cabbageTransplant · Apr 23 – May 7

Onion setsPlant outdoors · Apr 16 – Apr 30

PotatoesPlant outdoors · Apr 23 – May 7

LettuceSow outdoors · Apr 16 – Apr 30

Carrots, beetsSow outdoors · Apr 23 – May 7

TomatoesStart indoors · Mar 19 – Apr 2

TomatoesTransplant · May 21 – Jun 4

Peppers, eggplantStart indoors · Mar 5 – Mar 19

Peppers, eggplantTransplant · May 28 – Jun 11

BeansSow outdoors · May 21 – Jun 4

Sweet cornSow outdoors · May 21 – Jun 4

Cucumbers, squashSow outdoors · May 21 – Jun 4

Fall lettuce, spinachSow outdoors · Jul 28 – Aug 11

GarlicPlant cloves · Sep 8 – Oct 13

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 14) and first fall frost (Sep 22) 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 8a in Alaska

292 plants native to Alaska, recorded in Alaska, and rated by the USDA to survive 10 °F or colder — the bottom of zone 8a. 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 Tatitlek, AK.

Soil in Tatitlek, AK

The soil mapped at the center of ZIP 99677 is E20-maritime forest-loamy colluvial slopes, shallow — moderately decomposed plant material, moderately well drained.

TextureModerately decomposed plant materialtop layer

pH5.5moderately acidic; most vegetables like 6.0–7.0

DrainageModerately well drainednatural drainage class

Organic matter75%high

Hydrologic groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Alexander Archipelago-Gulf of Alaska Coast-Maritime Upland and Subalpine-Rounded 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 99677; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Tatitlek, AK

Summer high62 °Faverage high, July

Winter low15 °Faverage low, January

Hot days0days a year at 90 °F or more

Freezing nights191nights a year at 32 °F or less

Growing degree days391base 50 °F — the season’s usable heat

Longest day19 h 14 mindaylight on June 21

Shortest day5 h 34 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

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Valdez, AK (19 mi away); precipitation: Sugarloaf Mtn, AK (18 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

5 of the 5 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

Copper Center, AK · 57 mi

996744b

Sutton, AK · 67 mi

Alaska planting zones →

Questions about 99677

What planting zone is ZIP code 99677?

ZIP code 99677 (Tatitlek, AK) is in USDA hardiness zone 8a on the 2023 map: the coldest night of an average winter reaches 10 to 15 °F (−12.2 to −9.4 °C).

When is the last frost in Tatitlek, AK?

The median last spring frost (32 °F) near 99677 is May 14; after May 26 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Valdez station.

When is the first frost in Tatitlek, AK?

The median first fall frost near 99677 is September 22, giving a median frost-free growing season of 129 days.

When should I plant tomatoes in 99677?

Start tomato seeds indoors around Mar 19 – Apr 2 and set transplants outside around May 21 – Jun 4, one to three weeks after the median last frost.

How much rain and snow does 99677 get?

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

How hot do summers get in Tatitlek, 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 99677 have?

The USDA soil survey maps E20-maritime forest-loamy colluvial slopes, shallow at the center of ZIP 99677: moderately decomposed plant material, moderately well drained, pH about 5.5 (moderately acidic).

What kind of onions grow in Tatitlek, AK?

Long-day onions: the longest day near 99677 is 19 h 14 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 99677 change?

Yes. The 2012 USDA map put 99677 in zone 6b; the 2023 map puts it in zone 8a. The newer map uses 1991–2020 data and more weather stations.