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

Planting zone for 85655 — Douglas, AZ

ZIP code 85655 (Douglas, Cochise County) is in USDA zone 8a: the coldest winter night averages 10 to 15 °F. The median last spring frost is March 18 and the first fall frost November 13.

Where ZIP 85655 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.

Zone8a10 to 15 °F
Coldest night−12.2 to −9.4 °C
Last frostMar 18
First frostNov 13
2012 zone8a

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 8a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Douglas, 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 Douglas, AZ

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMarch 18median — 50% chance of a later frost
Safe for tender plantsApril 12only 10% chance of frost after
First fall frostNovember 13median — 10% chance by Oct 27
Growing season235 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 27 and returns around November 25.

From the NOAA station Douglas, AZ — within 1 mile, elevation 4,039 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 85655

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 4 – Feb 18
SpinachSow outdoors · Feb 4 – Feb 25
Broccoli, cabbageStart indoors · Jan 7 – Jan 21
Broccoli, cabbageTransplant · Feb 25 – Mar 11
Onion setsPlant outdoors · Feb 18 – Mar 4
PotatoesPlant outdoors · Feb 25 – Mar 11
LettuceSow outdoors · Feb 18 – Mar 4
Carrots, beetsSow outdoors · Feb 25 – Mar 11
TomatoesStart indoors · Jan 21 – Feb 4
TomatoesTransplant · Mar 25 – Apr 8
Peppers, eggplantStart indoors · Jan 7 – Jan 21
Peppers, eggplantTransplant · Apr 1 – Apr 15
BeansSow outdoors · Mar 25 – Apr 8
Sweet cornSow outdoors · Mar 25 – Apr 8
Cucumbers, squashSow outdoors · Mar 25 – Apr 8
Fall lettuce, spinachSow outdoors · Sep 18 – Oct 2
GarlicPlant cloves · Oct 30 – Dec 4
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 18) and first fall frost (Nov 13) 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 85655 came on Jan 31 — about the same time as the 1991–2020 average (Feb 2).

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 8a in Arizona

472 plants native to the lower 48 states, recorded in Arizona, and rated by the USDA to survive 10 °F or colder — the bottom of zone 8a. Each links to its USDA PLANTS profile.

Trees 24

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 100

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 195

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 eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °F

Grasses 144

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 Douglas, AZ.

Soil in Douglas, AZ

The soil mapped at the center of ZIP 85655 is Libby — very gravelly sandy loam, well drained.

TextureVery gravelly sandy loamdrains and warms fast; dries out and needs more feeding
pH7.9alkaline; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter0.25%low — add compost
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Libby-Gulch complex, 0 to 10 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 85655; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Douglas, AZ

Summer high97 °Faverage high, June
Winter low30 °Faverage low, December
Hot days116days a year at 90 °F or more
Freezing nights60nights a year at 32 °F or less
Growing degree days5,618base 50 °F — the season’s usable heat
Longest day14 h 11 mindaylight on June 21
Shortest day10 h 06 mindaylight on December 21
Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb
Precipitation14 inper year, rain and melted snow

Average high and low, by month

20°30°40°50°60°70°80°90°100°110°32 °FJanuary: average high 65 °F, low 31 °F 65°31° JanFebruary: average high 69 °F, low 35 °F 69°35° FebMarch: average high 73 °F, low 40 °F 73°40° MarApril: average high 81 °F, low 45 °F 81°45° AprMay: average high 89 °F, low 53 °F 89°53° MayJune: average high 97 °F, low 62 °F 97°62° JunJuly: average high 95 °F, low 66 °F 95°66° JulAugust: average high 93 °F, low 65 °F 93°65° AugSeptember: average high 90 °F, low 60 °F 90°60° SepOctober: average high 83 °F, low 49 °F 83°49° OctNovember: average high 74 °F, low 38 °F 74°38° NovDecember: average high 65 °F, low 30 °F 65°30° Dec

Precipitation by month inches

0″1″2″3″4″January: 0.91 in precipitation 0.9 JanFebruary: 0.74 in precipitation 0.7 FebMarch: 0.61 in precipitation 0.6 MarApril: 0.17 in precipitation 0.2 AprMay: 0.40 in precipitation 0.4 MayJune: 0.53 in precipitation 0.5 JunJuly: 3.45 in precipitation 3.5 JulAugust: 3.20 in precipitation 3.2 AugSeptember: 1.67 in precipitation 1.7 SepOctober: 0.78 in precipitation 0.8 OctNovember: 0.64 in precipitation 0.6 NovDecember: 0.86 in precipitation 0.9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Douglas, AZ (within 1 mile); precipitation: Douglas, AZ (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

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

856268a
Pirtleville, AZ · 2 mi
856088a
Douglas, AZ · 8 mi
856078a
Douglas, AZ · 16 mi
856178b
Mc Neal, AZ · 19 mi
856038b
Bisbee, AZ · 23 mi
856208b
Naco, AZ · 23 mi
856108b
Elfrida, AZ · 28 mi
856258a
Pearce, AZ · 37 mi

All 3 ZIP codes in Douglas → · Arizona planting zones →

Questions about 85655

What planting zone is ZIP code 85655?

ZIP code 85655 (Douglas, AZ) 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 Douglas, AZ?

The median last spring frost (32 °F) near 85655 is March 18; after April 12 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Douglas station.

When is the first frost in Douglas, AZ?

The median first fall frost near 85655 is November 13, giving a median frost-free growing season of 235 days.

When should I plant tomatoes in 85655?

Start tomato seeds indoors around Jan 21 – Feb 4 and set transplants outside around Mar 25 – Apr 8, one to three weeks after the median last frost.

How much rain and snow does 85655 get?

About 14 inches of precipitation a year (NOAA 1991–2020 normals, Douglas station).

How hot do summers get in Douglas, AZ?

The average high peaks at 97 °F in June, with about 116 days a year at 90 °F or more.

What kind of soil does 85655 have?

The USDA soil survey maps Libby at the center of ZIP 85655: very gravelly sandy loam, well drained, pH about 7.9 (alkaline).

Did spring come early in Douglas, AZ in 2026?

Spring leaf-out near 85655 came on Jan 31 in 2026, about the same as the 1991–2020 average (Feb 2), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Douglas, AZ?

Short-day onions: the longest day near 85655 is 14 h 11 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.