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

Planting zone for 85670 — Fort Huachuca, AZ

ZIP code 85670 (Fort Huachuca, Cochise County) is in USDA zone 8b: the coldest winter night averages 15 to 20 °F. The median last spring frost is April 14 and the first fall frost November 2.

Where ZIP 85670 is

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.

Zone8b15 to 20 °F
Coldest night−9.4 to −6.7 °C
Last frostApr 14
First frostNov 2
2012 zone8b

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 8b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Fort Huachuca, AZ…

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 Fort Huachuca, AZ

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 14median — 50% chance of a later frost
Safe for tender plantsApril 30only 10% chance of frost after
First fall frostNovember 2median — 10% chance by Oct 20
Growing season200 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 27 and returns around November 13.

From the NOAA station Pearce - Sunsites, AZ — 6 miles away, elevation 4,351 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 85670

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 3 – Mar 17
SpinachSow outdoors · Mar 3 – Mar 24
Broccoli, cabbageStart indoors · Feb 3 – Feb 17
Broccoli, cabbageTransplant · Mar 24 – Apr 7
Onion setsPlant outdoors · Mar 17 – Mar 31
PotatoesPlant outdoors · Mar 24 – Apr 7
LettuceSow outdoors · Mar 17 – Mar 31
Carrots, beetsSow outdoors · Mar 24 – Apr 7
TomatoesStart indoors · Feb 17 – Mar 3
TomatoesTransplant · Apr 21 – May 5
Peppers, eggplantStart indoors · Feb 3 – Feb 17
Peppers, eggplantTransplant · Apr 28 – May 12
BeansSow outdoors · Apr 21 – May 5
Sweet cornSow outdoors · Apr 21 – May 5
Cucumbers, squashSow outdoors · Apr 21 – May 5
Fall lettuce, spinachSow outdoors · Sep 7 – Sep 21
GarlicPlant cloves · Oct 19 – Nov 23
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 14) and first fall frost (Nov 2) 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.

When spring arrived in 2026

In 2026, spring leaf-out near 85670 came on Feb 4 — about the same time as the 1991–2020 average (Feb 4).

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Native plants for zone 8b in Arizona

482 plants native to the lower 48 states, recorded in Arizona, and rated by the USDA to survive 15 °F or colder — the bottom of zone 8b. Each links to its USDA PLANTS profile.

Trees 25

Arizona cypress50 ft · blooms spring · low shade tolerance · to −23 °FArizona madrone30 ft · blooms late spring · high shade tolerance · to −4 °FArizona sycamore80 ft · blooms early spring · high shade tolerance · to −8 °FArizona walnut50 ft · blooms late spring · high shade tolerance · to −33 °Fblack locust60 ft · blooms spring · high shade tolerance · to −37 °Fblue spruce100 ft · blooms late spring · medium shade tolerance · to −38 °F

Shrubs 105

alderleaf mountain mahogany15 ft · blooms late spring · medium shade tolerance · to −41 °FAmerican plum24 ft · blooms mid spring · high shade tolerance · to −38 °FAmerican tarwort3 ft · blooms late spring · high shade tolerance · to −23 °Fantelope bitterbrush6 ft · blooms early spring · medium shade tolerance · to −36 °FApache plume6 ft · blooms late spring · high shade tolerance · to −23 °Fbig sagebrush4 ft · blooms mid summer · high shade tolerance · to −43 °F

Wildflowers & perennials 196

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °Falpine mountainsorrel1 ft · blooms mid summer · medium shade tolerance · to −43 °FAmerican alpine speedwell1 ft · blooms summer · medium shade tolerance · to −28 °FAmerican bistort1.5 ft · blooms mid spring · high shade tolerance · to −38 °FAmerican century plant6 ft · blooms indeterminate · high shade tolerance · to 12 °F

Grasses 147

alkali cordgrass3 ft · blooms late summer · high shade tolerance · to −38 °Falkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °Falpine timothy1.4 ft · blooms late spring · medium shade tolerance · to −43 °Fanalogue sedge1.5 ft · blooms late spring · medium shade tolerance · to −38 °FArizona cottontop4 ft · blooms late summer · high shade tolerance · to −13 °FArizona fescue2 ft · blooms late spring · high shade tolerance · to −23 °F

Vines 1

western white clematis1 ft · blooms mid summer · medium shade tolerance · to −38 °F

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 Fort Huachuca, AZ.

Soil in Fort Huachuca, AZ

The soil mapped at the center of ZIP 85670 is Eloma — very gravelly sandy loam, well drained.

TextureVery gravelly sandy loamdrains and warms fast; dries out and needs more feeding
pH7.4slightly alkaline; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.5%low — add compost
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Eloma-Caralampi-White House complex, 1 to 15 percent slopes.

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 85670; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Fort Huachuca, AZ

Summer high95 °Faverage high, June
Winter low29 °Faverage low, January
Hot days94days a year at 90 °F or more
Freezing nights83nights a year at 32 °F or less
Growing degree days4,797base 50 °F — the season’s usable heat
Longest day14 h 14 mindaylight on June 21
Shortest day10 h 04 mindaylight on December 21
Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb
Precipitation12.2 inper year, rain and melted snow
Snowfall1 inper year

Average high and low, by month

20°30°40°50°60°70°80°90°100°110°32 °FJanuary: average high 60 °F, low 29 °F 60°29° JanFebruary: average high 64 °F, low 32 °F 64°32° FebMarch: average high 70 °F, low 37 °F 70°37° MarApril: average high 78 °F, low 42 °F 78°42° AprMay: average high 86 °F, low 50 °F 86°50° MayJune: average high 95 °F, low 59 °F 95°59° JunJuly: average high 93 °F, low 65 °F 93°65° JulAugust: average high 91 °F, low 64 °F 91°64° AugSeptember: average high 88 °F, low 57 °F 88°57° SepOctober: average high 80 °F, low 46 °F 80°46° OctNovember: average high 69 °F, low 36 °F 69°36° NovDecember: average high 59 °F, low 29 °F 59°29° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″January: 0.85 in precipitation, 0.7 in snowfall 0.8❄1 JanFebruary: 0.75 in precipitation, 0.2 in snowfall 0.8 FebMarch: 0.55 in precipitation, 0.1 in snowfall 0.6 MarApril: 0.19 in precipitation 0.2 AprMay: 0.23 in precipitation 0.2 MayJune: 0.56 in precipitation 0.6 JunJuly: 2.58 in precipitation 2.6 JulAugust: 2.86 in precipitation 2.9 AugSeptember: 1.47 in precipitation 1.5 SepOctober: 0.68 in precipitation 0.7 OctNovember: 0.67 in precipitation, 0.2 in snowfall 0.7 NovDecember: 0.80 in precipitation 0.8 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Pearce - Sunsites, AZ (6 mi away); precipitation: Pearce - Sunsites, AZ (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

856258a
Pearce, AZ · 5 mi
856108b
Elfrida, AZ · 11 mi
856068b
Cochise, AZ · 13 mi
856178b
Mc Neal, AZ · 21 mi
856388b
Tombstone, AZ · 23 mi
856098b
Dragoon, AZ · 24 mi
856308b
Saint David, AZ · 25 mi
856278b
Pomerene, AZ · 30 mi

All 2 ZIP codes in Fort Huachuca → · Arizona planting zones →

Questions about 85670

What planting zone is ZIP code 85670?

ZIP code 85670 (Fort Huachuca, AZ) is in USDA hardiness zone 8b on the 2023 map: the coldest night of an average winter reaches 15 to 20 °F (−9.4 to −6.7 °C).

When is the last frost in Fort Huachuca, AZ?

The median last spring frost (32 °F) near 85670 is April 14; after April 30 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Pearce - Sunsites station.

When is the first frost in Fort Huachuca, AZ?

The median first fall frost near 85670 is November 2, giving a median frost-free growing season of 200 days.

When should I plant tomatoes in 85670?

Start tomato seeds indoors around Feb 17 – Mar 3 and set transplants outside around Apr 21 – May 5, one to three weeks after the median last frost.

How much rain and snow does 85670 get?

About 12.2 inches of precipitation a year and 1 inches of snowfall (NOAA 1991–2020 normals, Pearce - Sunsites station).

How hot do summers get in Fort Huachuca, AZ?

The average high peaks at 95 °F in June, with about 94 days a year at 90 °F or more.

What kind of soil does 85670 have?

The USDA soil survey maps Eloma at the center of ZIP 85670: very gravelly sandy loam, well drained, pH about 7.4 (slightly alkaline).

Did spring come early in Fort Huachuca, AZ in 2026?

Spring leaf-out near 85670 came on Feb 4 in 2026, about the same as the 1991–2020 average (Feb 4), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Fort Huachuca, AZ?

Short-day onions: the longest day near 85670 is 14 h 14 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.