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

Planting zone for 99702 — Eielson Afb, AK

ZIP code 99702 (Eielson Afb, Fairbanks North Star County) is in USDA zone 2a: the coldest winter night averages −50 to −45 °F. The median last spring frost is May 20 and the first fall frost September 1.

Where ZIP 99702 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 20
First frostSep 1
2012 zone2a

Same zone as on the 2012 map. 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 Eielson Afb, 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 Eielson Afb, AK

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 20median — 50% chance of a later frost
Safe for tender plantsJune 3only 10% chance of frost after
First fall frostSeptember 1median — 10% chance by Aug 20
Growing season104 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 10 and returns around September 14.

From the NOAA station Eielson Field, AK — 2 miles away, elevation 548 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 99702

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Apr 8 – Apr 22
SpinachSow outdoors · Apr 8 – Apr 29
Broccoli, cabbageStart indoors · Mar 11 – Mar 25
Broccoli, cabbageTransplant · Apr 29 – May 13
Onion setsPlant outdoors · Apr 22 – May 6
PotatoesPlant outdoors · Apr 29 – May 13
LettuceSow outdoors · Apr 22 – May 6
Carrots, beetsSow outdoors · Apr 29 – May 13
TomatoesStart indoors · Mar 25 – Apr 8
TomatoesTransplant · May 27 – Jun 10
Peppers, eggplantStart indoors · Mar 11 – Mar 25
Peppers, eggplantTransplant · Jun 3 – Jun 17
BeansSow outdoors · May 27 – Jun 10
Sweet cornSow outdoors · May 27 – Jun 10
Cucumbers, squashSow outdoors · May 27 – Jun 10
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 20) 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.

Soil in Eielson Afb, AK

The soil mapped at the center of ZIP 99702 is 29-Jarvis — moderately decomposed plant material, well drained.

TextureModerately decomposed plant materialtop layer
pH6.1slightly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter90%high
Hydrologic groupBwater soaks in moderately
Farmland classFarmland of local importanceUSDA classification

Map unit: Jarvis-Salchaket complex.

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 99702; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Eielson Afb, AK

Summer high72 °Faverage high, July
Winter low−18 °Faverage low, January
Hot days0days a year at 90 °F or more
Freezing nights223nights a year at 32 °F or less
Growing degree days868base 50 °F — the season’s usable heat
Longest day21 h 38 mindaylight on June 21
Shortest day3 h 49 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation12.9 inper year, rain and melted snow
Snowfall68 inper year

Average high and low, by month

−30°−20°−10°0°10°20°30°40°50°60°70°80°32 °FJanuary: average high 0 °F, low -18 °F 0°−18° JanFebruary: average high 11 °F, low -11 °F 11°−11° FebMarch: average high 25 °F, low -3 °F 25°−3° MarApril: average high 45 °F, low 21 °F 45°21° AprMay: average high 61 °F, low 36 °F 61°36° MayJune: average high 71 °F, low 47 °F 71°47° JunJuly: average high 72 °F, low 50 °F 72°50° JulAugust: average high 66 °F, low 44 °F 66°44° AugSeptember: average high 54 °F, low 34 °F 54°34° SepOctober: average high 33 °F, low 16 °F 33°16° OctNovember: average high 10 °F, low -6 °F 10°−6° NovDecember: average high 3 °F, low -14 °F 3°−14° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″January: 0.48 in precipitation, 8.5 in snowfall 0.5❄9 JanFebruary: 0.37 in precipitation, 6.5 in snowfall 0.4❄7 FebMarch: 0.32 in precipitation, 6.9 in snowfall 0.3❄7 MarApril: 0.32 in precipitation, 3.5 in snowfall 0.3❄4 AprMay: 0.69 in precipitation, 1.7 in snowfall 0.7❄2 MayJune: 2.12 in precipitation 2.1 JunJuly: 2.67 in precipitation 2.7 JulAugust: 2.61 in precipitation 2.6 AugSeptember: 1.49 in precipitation, 2.6 in snowfall 1.5❄3 SepOctober: 0.87 in precipitation, 12.9 in snowfall 0.9❄13 OctNovember: 0.52 in precipitation, 13.4 in snowfall 0.5❄13 NovDecember: 0.42 in precipitation, 11.7 in snowfall 0.4❄12 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Eielson Field, AK (2 mi away); precipitation: Eielson Field, AK (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

997052a
North Pole, AK · 11 mi
997162a
Two Rivers, AK · 16 mi
997032a
Fort Wainwright, AK · 21 mi
997102b
Fairbanks, AK · 24 mi
997112a
Fairbanks, AK · 24 mi
997143b
Salcha, AK · 24 mi
997752b
Fairbanks, AK · 27 mi
997082a
Fairbanks, AK · 31 mi

Alaska planting zones →

Questions about 99702

What planting zone is ZIP code 99702?

ZIP code 99702 (Eielson Afb, 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 Eielson Afb, AK?

The median last spring frost (32 °F) near 99702 is May 20; after June 3 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Eielson Field station.

When is the first frost in Eielson Afb, AK?

The median first fall frost near 99702 is September 1, giving a median frost-free growing season of 104 days.

When should I plant tomatoes in 99702?

Start tomato seeds indoors around Mar 25 – Apr 8 and set transplants outside around May 27 – Jun 10, one to three weeks after the median last frost.

How much rain and snow does 99702 get?

About 12.9 inches of precipitation a year and 68 inches of snowfall (NOAA 1991–2020 normals, Eielson Field station).

How hot do summers get in Eielson Afb, AK?

The average high peaks at 72 °F in July, with about 0 days a year at 90 °F or more.

What kind of soil does 99702 have?

The USDA soil survey maps 29-Jarvis at the center of ZIP 99702: moderately decomposed plant material, well drained, pH about 6.1 (slightly acidic).

What kind of onions grow in Eielson Afb, AK?

Long-day onions: the longest day near 99702 is 21 h 38 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).