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

Planting zone for 85178 — Apache Junction, AZ

ZIP code 85178 (Apache Junction, Pinal County) is in USDA zone 9b: the coldest winter night averages 25 to 30 °F. The median last spring frost is February 11 and the first fall frost December 10.

Where ZIP 85178 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.

Zone9b25 to 30 °F
Coldest night−3.9 to −1.1 °C
Last frostFeb 11
First frostDec 10
2012 zone9b

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 9b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Apache Junction, 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 Apache Junction, AZ

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostFebruary 11median — 50% chance of a later frost
Safe for tender plantsMarch 7only 10% chance of frost after
First fall frostDecember 10median — 10% chance by Nov 19
Growing season304 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 13 and returns around December 22.

From the NOAA station Apache Junction 5 Ne, AZ — 6 miles away, elevation 2,070 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 85178

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Dec 31 – Jan 14
SpinachSow outdoors · Dec 31 – Jan 21
Broccoli, cabbageStart indoors · Dec 3 – Dec 17
Broccoli, cabbageTransplant · Jan 21 – Feb 4
Onion setsPlant outdoors · Jan 14 – Jan 28
PotatoesPlant outdoors · Jan 21 – Feb 4
LettuceSow outdoors · Jan 14 – Jan 28
Carrots, beetsSow outdoors · Jan 21 – Feb 4
TomatoesStart indoors · Dec 17 – Dec 31
TomatoesTransplant · Feb 18 – Mar 4
Peppers, eggplantStart indoors · Dec 3 – Dec 17
Peppers, eggplantTransplant · Feb 25 – Mar 11
BeansSow outdoors · Feb 18 – Mar 4
Sweet cornSow outdoors · Feb 18 – Mar 4
Cucumbers, squashSow outdoors · Feb 18 – Mar 4
Fall lettuce, spinachSow outdoors · Oct 15 – Oct 29
GarlicPlant cloves · Nov 26 – Dec 31
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 11) and first fall frost (Dec 10) 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 85178 came on Jan 19 — 4 days earlier than the 1991–2020 average (Jan 23).

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 9b in Arizona

499 plants native to the lower 48 states, recorded in Arizona, and rated by the USDA to survive 25 °F or colder — the bottom of zone 9b. Each links to its USDA PLANTS profile.

Trees 26

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 113

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 199

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 152

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 Apache Junction, AZ.

Soil in Apache Junction, AZ

The soil mapped at the center of ZIP 85178 is Tremant — gravelly loam, well drained.

TextureGravelly loama good balance for most vegetables
pH8.2alkaline; 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: Tremant gravelly loams.

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 85178; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Apache Junction, AZ

Summer high105 °Faverage high, July
Winter low42 °Faverage low, December
Hot days168days a year at 90 °F or more
Freezing nights8nights a year at 32 °F or less
Growing degree days8,111base 50 °F — the season’s usable heat
Longest day14 h 22 mindaylight on June 21
Shortest day9 h 56 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation9.6 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°100°110°120°32 °FJanuary: average high 67 °F, low 43 °F 67°43° JanFebruary: average high 70 °F, low 44 °F 70°44° FebMarch: average high 77 °F, low 48 °F 77°48° MarApril: average high 85 °F, low 53 °F 85°53° AprMay: average high 93 °F, low 60 °F 93°60° MayJune: average high 103 °F, low 69 °F 103°69° JunJuly: average high 105 °F, low 77 °F 105°77° JulAugust: average high 104 °F, low 76 °F 104°76° AugSeptember: average high 99 °F, low 71 °F 99°71° SepOctober: average high 88 °F, low 60 °F 88°60° OctNovember: average high 76 °F, low 50 °F 76°50° NovDecember: average high 66 °F, low 42 °F 66°42° Dec

Precipitation by month inches

0″1″2″January: 1.23 in precipitation 1.2 JanFebruary: 1.20 in precipitation 1.2 FebMarch: 1.10 in precipitation 1.1 MarApril: 0.32 in precipitation 0.3 AprMay: 0.23 in precipitation 0.2 MayJune: 0.04 in precipitation 0.0 JunJuly: 1.14 in precipitation 1.1 JulAugust: 1.13 in precipitation 1.1 AugSeptember: 0.81 in precipitation 0.8 SepOctober: 0.69 in precipitation 0.7 OctNovember: 0.70 in precipitation 0.7 NovDecember: 1.00 in precipitation 1.0 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Apache Junction 5 Ne, AZ (6 mi away); precipitation: Apache Junction 2.5 Wsw, AZ (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 9b.

851209b
Apache Junction, AZ · 2 mi
851199b
Apache Junction, AZ · 3 mi
852089b
Mesa, AZ · 5 mi
852099b
Mesa, AZ · 5 mi
852079b
Mesa, AZ · 6 mi
852129b
Mesa, AZ · 8 mi
852159b
Mesa, AZ · 8 mi
852069b
Mesa, AZ · 10 mi

All 4 ZIP codes in Apache Junction → · Arizona planting zones →

Questions about 85178

What planting zone is ZIP code 85178?

ZIP code 85178 (Apache Junction, AZ) is in USDA hardiness zone 9b on the 2023 map: the coldest night of an average winter reaches 25 to 30 °F (−3.9 to −1.1 °C).

When is the last frost in Apache Junction, AZ?

The median last spring frost (32 °F) near 85178 is February 11; after March 7 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Apache Junction 5 Ne station.

When is the first frost in Apache Junction, AZ?

The median first fall frost near 85178 is December 10, giving a median frost-free growing season of 304 days.

When should I plant tomatoes in 85178?

Start tomato seeds indoors around Dec 17 – Dec 31 and set transplants outside around Feb 18 – Mar 4, one to three weeks after the median last frost.

How much rain and snow does 85178 get?

About 9.6 inches of precipitation a year (NOAA 1991–2020 normals, Apache Junction 2.5 Wsw station).

How hot do summers get in Apache Junction, AZ?

The average high peaks at 105 °F in July, with about 168 days a year at 90 °F or more.

What kind of soil does 85178 have?

The USDA soil survey maps Tremant at the center of ZIP 85178: gravelly loam, well drained, pH about 8.2 (alkaline).

Did spring come early in Apache Junction, AZ in 2026?

Spring leaf-out near 85178 came on Jan 19 in 2026, 4 days earlier than the 1991–2020 average (Jan 23), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Apache Junction, AZ?

Intermediate onions: the longest day near 85178 is 14 h 22 min, so day-neutral types bulb best; long-day varieties may not bulb fully.