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

Planting zone for 99656 — Red Devil, AK

ZIP code 99656 (Red Devil, Bethel Census Area County) is in USDA zone 3a: the coldest winter night averages −40 to −35 °F.

Where ZIP 99656 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.

Zone3a−40 to −35 °F
Coldest night−40 to −37.2 °C
Last frostrare
First frostrare
2012 zone2a

Was 2a 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 3a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Red Devil, 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

No NOAA station with frost records lies within 90 miles of Red Devil, AK, so we don't show frost dates here rather than guess. Your local extension office can give you a date.

Soil in Red Devil, AK

The soil mapped at the center of ZIP 99656 is 30-Subalpine woodland, gravelly colluvial slopes — slightly decomposed plant material, well drained.

TextureSlightly decomposed plant materialtop layer
pH4.0strongly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter90%high
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Yukon-Kuskokwim Highlands, Boreal and Subalpine 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 99656; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Red Devil, AK

Longest day19 h 41 mindaylight on June 21
Shortest day5 h 12 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)

Daylight is calculated from latitude.

Nearby ZIP codes

2 of the 4 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

996682b
Sleetmute, AK · 17 mi
995753a
Crooked Creek, AK · 24 mi
995033a
Anchorage, AK · 29 mi
996752a
Takotna, AK · 88 mi

Alaska planting zones →

Questions about 99656

What planting zone is ZIP code 99656?

ZIP code 99656 (Red Devil, AK) is in USDA hardiness zone 3a on the 2023 map: the coldest night of an average winter reaches −40 to −35 °F (−40 to −37.2 °C).

What kind of soil does 99656 have?

The USDA soil survey maps 30-Subalpine woodland, gravelly colluvial slopes at the center of ZIP 99656: slightly decomposed plant material, well drained, pH about 4.0 (strongly acidic).

What kind of onions grow in Red Devil, AK?

Long-day onions: the longest day near 99656 is 19 h 41 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 99656 change?

Yes. The 2012 USDA map put 99656 in zone 2a; the 2023 map puts it in zone 3a. The newer map uses 1991–2020 data and more weather stations.