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

Planting zone for 99780 — Tok, AK

ZIP code 99780 (Tok, Southeast Fairbanks Census Area County) is in USDA zone 2a: the coldest winter night averages −50 to −45 °F. The median last spring frost is May 26 and the first fall frost September 1.

Where ZIP 99780 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.

Zone2a−50 to −45 °F

Coldest night−45.6 to −42.8 °C

Last frostMay 26

First frostSep 1

2012 zone1a

Was 1a 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 2a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Tok, 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 Tok, AK

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 26median — 50% chance of a later frost

Safe for tender plantsJune 8only 10% chance of frost after

First fall frostSeptember 1median — 10% chance by Aug 18

Growing season97 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 13 and returns around September 13.

From the NOAA station Northway Airport, AK — 48 miles away, elevation 1,713 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 99780

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 14 – Apr 28

SpinachSow outdoors · Apr 14 – May 5

Broccoli, cabbageStart indoors · Mar 17 – Mar 31

Broccoli, cabbageTransplant · May 5 – May 19

Onion setsPlant outdoors · Apr 28 – May 12

PotatoesPlant outdoors · May 5 – May 19

LettuceSow outdoors · Apr 28 – May 12

Carrots, beetsSow outdoors · May 5 – May 19

TomatoesStart indoors · Mar 31 – Apr 14

TomatoesTransplant · Jun 2 – Jun 16

Peppers, eggplantStart indoors · Mar 17 – Mar 31

Peppers, eggplantTransplant · Jun 9 – Jun 23

BeansSow outdoors · Jun 2 – Jun 16

Sweet cornSow outdoors · Jun 2 – Jun 16

Cucumbers, squashSow outdoors · Jun 2 – Jun 16

Fall lettuce, spinachSow outdoors · Jul 7 – Jul 21

GarlicPlant cloves · Aug 18 – Sep 22

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 26) and first fall frost (Sep 1) 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 2a in Alaska

44 plants native to Alaska, recorded in Alaska, and rated by the USDA to survive −50 °F or colder — the bottom of zone 2a. 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 Tok, AK.

Soil in Tok, AK

The soil mapped at the center of ZIP 99780 is E31-Boreal forest-silty slopes — slightly decomposed plant material, well drained.

TextureSlightly decomposed plant materialtop layer

pH3.5strongly 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: Interior Alaska Highlands-Boreal Upland-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 99780; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Tok, AK

Summer high70 °Faverage high, July

Winter low−29 °Faverage low, January

Hot days0days a year at 90 °F or more

Freezing nights274nights a year at 32 °F or less

Growing degree days432base 50 °F — the season’s usable heat

Longest day20 h 45 mindaylight on June 21

Shortest day4 h 24 mindaylight on December 21

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

Precipitation12.3 inper year, rain and melted snow

Snowfall37 inper year; 200 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: Chicken, AK (34 mi away); precipitation: Chicken, AK (34 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

Alaska planting zones →

Questions about 99780

What planting zone is ZIP code 99780?

ZIP code 99780 (Tok, AK) is in USDA hardiness zone 2a on the 2023 map: the coldest night of an average winter reaches −50 to −45 °F (−45.6 to −42.8 °C).

When is the last frost in Tok, AK?

The median last spring frost (32 °F) near 99780 is May 26; after June 8 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Northway Airport station.

When is the first frost in Tok, AK?

The median first fall frost near 99780 is September 1, giving a median frost-free growing season of 97 days.

When should I plant tomatoes in 99780?

Start tomato seeds indoors around Mar 31 – Apr 14 and set transplants outside around Jun 2 – Jun 16, one to three weeks after the median last frost.

How much rain and snow does 99780 get?

About 12.3 inches of precipitation a year and 37 inches of snowfall (NOAA 1991–2020 normals, Chicken station).

How hot do summers get in Tok, AK?

The average high peaks at 70 °F in July, with about 0 days a year at 90 °F or more.

What kind of soil does 99780 have?

The USDA soil survey maps E31-Boreal forest-silty slopes at the center of ZIP 99780: slightly decomposed plant material, well drained, pH about 3.5 (strongly acidic).

What kind of onions grow in Tok, AK?

Long-day onions: the longest day near 99780 is 20 h 45 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 99780 change?

Yes. The 2012 USDA map put 99780 in zone 1a; the 2023 map puts it in zone 2a. The newer map uses 1991–2020 data and more weather stations.