Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 85328 — Cibola, AZ

ZIP code 85328 (Cibola, La Paz County) is in USDA zone 9b: the coldest winter night averages 25 to 30 °F. The median last spring frost is January 25 and the first fall frost December 12.

Where ZIP 85328 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.

Zone9b25 to 30 °F

Coldest night−3.9 to −1.1 °C

Last frostJan 25

First frostDec 12

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 Cibola, 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 Cibola, AZ

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostJanuary 25median — 50% chance of a later frost

Safe for tender plantsFebruary 24only 10% chance of frost after

First fall frostDecember 12median — 10% chance by Nov 28

Growing season325 daysfrost-free, median

A hard freeze (28 °F) usually ends around December 30 and returns around December 22.

From the NOAA station Blythe, CA — 25 miles away, elevation 269 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 85328

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Dec 14 – Dec 28

SpinachSow outdoors · Dec 14 – Jan 4

Broccoli, cabbageStart indoors · Nov 16 – Nov 30

Broccoli, cabbageTransplant · Jan 4 – Jan 18

Onion setsPlant outdoors · Dec 28 – Jan 11

PotatoesPlant outdoors · Jan 4 – Jan 18

LettuceSow outdoors · Dec 28 – Jan 11

Carrots, beetsSow outdoors · Jan 4 – Jan 18

TomatoesStart indoors · Nov 30 – Dec 14

TomatoesTransplant · Feb 1 – Feb 15

Peppers, eggplantStart indoors · Nov 16 – Nov 30

Peppers, eggplantTransplant · Feb 8 – Feb 22

BeansSow outdoors · Feb 1 – Feb 15

Sweet cornSow outdoors · Feb 1 – Feb 15

Cucumbers, squashSow outdoors · Feb 1 – Feb 15

Fall lettuce, spinachSow outdoors · Oct 17 – Oct 31

GarlicPlant cloves · Nov 28 – Jan 2

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jan 25) and first fall frost (Dec 12) 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 85328 came on Jan 21 — about the same time as the 1991–2020 average (Jan 23).

average
Jan 232026
Jan 21

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.

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 Cibola, AZ.

Soil in Cibola, AZ

The soil mapped at the center of ZIP 85328 is Laposa — extremely gravelly loam, well drained.

TextureExtremely gravelly loama good balance for most vegetables

pH8.2alkaline; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter0.5%low — add compost

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Laposa-Rock outcrop complex, 15 to 75 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 85328; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Cibola, AZ

Summer high110 °Faverage high, July

Winter low38 °Faverage low, December

Hot days188days a year at 90 °F or more

Freezing nights9nights a year at 32 °F or less

Growing degree days8,641base 50 °F — the season’s usable heat

Longest day14 h 21 mindaylight on June 21

Shortest day9 h 57 mindaylight on December 21

Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully

Precipitation3.6 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Blythe, CA (25 mi away); precipitation: Blythe, CA (25 mi away). 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.

9226610a

Palo Verde, CA · 17 mi

922269b

Blythe, CA · 24 mi

9228310a

Winterhaven, CA · 26 mi

853349b

Ehrenberg, AZ · 28 mi

Quartzsite, AZ · 36 mi

Arizona planting zones →

Questions about 85328

What planting zone is ZIP code 85328?

ZIP code 85328 (Cibola, 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 Cibola, AZ?

The median last spring frost (32 °F) near 85328 is January 25; after February 24 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Blythe station.

When is the first frost in Cibola, AZ?

The median first fall frost near 85328 is December 12, giving a median frost-free growing season of 325 days.

When should I plant tomatoes in 85328?

Start tomato seeds indoors around Nov 30 – Dec 14 and set transplants outside around Feb 1 – Feb 15, one to three weeks after the median last frost.

How much rain and snow does 85328 get?

About 3.6 inches of precipitation a year (NOAA 1991–2020 normals, Blythe station).

How hot do summers get in Cibola, AZ?

The average high peaks at 110 °F in July, with about 188 days a year at 90 °F or more.

What kind of soil does 85328 have?

The USDA soil survey maps Laposa at the center of ZIP 85328: extremely gravelly loam, well drained, pH about 8.2 (alkaline).

Did spring come early in Cibola, AZ in 2026?

Spring leaf-out near 85328 came on Jan 21 in 2026, about the same as the 1991–2020 average (Jan 23), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Cibola, AZ?

Intermediate onions: the longest day near 85328 is 14 h 21 min, so day-neutral types bulb best; long-day varieties may not bulb fully.