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

Planting zone for 85141 — Picacho, AZ

ZIP code 85141 (Picacho, Pinal County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is February 6 and the first fall frost December 9.

Where ZIP 85141 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.

Zone9a20 to 25 °F

Coldest night−6.7 to −3.9 °C

Last frostFeb 6

First frostDec 9

2012 zone9a

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 9a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Picacho, 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 Picacho, AZ

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostFebruary 6median — 50% chance of a later frost

Safe for tender plantsMarch 5only 10% chance of frost after

First fall frostDecember 9median — 10% chance by Nov 22

Growing season308 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 14 and returns around December 19.

From the NOAA station Picacho 8 Se, AZ — 2 miles away, elevation 1,982 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 85141

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Dec 26 – Jan 9

SpinachSow outdoors · Dec 26 – Jan 16

Broccoli, cabbageStart indoors · Nov 28 – Dec 12

Broccoli, cabbageTransplant · Jan 16 – Jan 30

Onion setsPlant outdoors · Jan 9 – Jan 23

PotatoesPlant outdoors · Jan 16 – Jan 30

LettuceSow outdoors · Jan 9 – Jan 23

Carrots, beetsSow outdoors · Jan 16 – Jan 30

TomatoesStart indoors · Dec 12 – Dec 26

TomatoesTransplant · Feb 13 – Feb 27

Peppers, eggplantStart indoors · Nov 28 – Dec 12

Peppers, eggplantTransplant · Feb 20 – Mar 6

BeansSow outdoors · Feb 13 – Feb 27

Sweet cornSow outdoors · Feb 13 – Feb 27

Cucumbers, squashSow outdoors · Feb 13 – Feb 27

Fall lettuce, spinachSow outdoors · Oct 14 – Oct 28

GarlicPlant cloves · Nov 25 – Dec 30

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 6) and first fall frost (Dec 9) 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 85141 came on Jan 26 — about the same time as the 1991–2020 average (Jan 25).

average
Jan 252026
Jan 26

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 9a in Arizona

492 plants native to the lower 48 states, recorded in Arizona, and rated by the USDA to survive 20 °F or colder — the bottom of zone 9a. 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 Picacho, AZ.

Soil in Picacho, AZ

The soil mapped at the center of ZIP 85141 is Pinamt — very gravelly loam, well drained.

TextureVery gravelly 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: Pinamt-Momoli complex, 1 to 8 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 85141; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Picacho, AZ

Summer high104 °Faverage high, June

Winter low40 °Faverage low, December

Hot days176days a year at 90 °F or more

Freezing nights10nights a year at 32 °F or less

Growing degree days8,248base 50 °F — the season’s usable heat

Longest day14 h 18 mindaylight on June 21

Shortest day10 h 00 mindaylight on December 21

Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb

Precipitation9.9 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: Picacho 8 Se, AZ (2 mi away); precipitation: Picacho 8 Se, AZ (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

Arizona City, AZ · 15 mi

Casa Grande, AZ · 20 mi

851949a

Casa Grande, AZ · 21 mi

851289a

Coolidge, AZ · 23 mi

Arizona planting zones →

Questions about 85141

What planting zone is ZIP code 85141?

ZIP code 85141 (Picacho, AZ) is in USDA hardiness zone 9a on the 2023 map: the coldest night of an average winter reaches 20 to 25 °F (−6.7 to −3.9 °C).

When is the last frost in Picacho, AZ?

The median last spring frost (32 °F) near 85141 is February 6; after March 5 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Picacho 8 Se station.

When is the first frost in Picacho, AZ?

The median first fall frost near 85141 is December 9, giving a median frost-free growing season of 308 days.

When should I plant tomatoes in 85141?

Start tomato seeds indoors around Dec 12 – Dec 26 and set transplants outside around Feb 13 – Feb 27, one to three weeks after the median last frost.

How much rain and snow does 85141 get?

About 9.9 inches of precipitation a year (NOAA 1991–2020 normals, Picacho 8 Se station).

How hot do summers get in Picacho, AZ?

The average high peaks at 104 °F in June, with about 176 days a year at 90 °F or more.

What kind of soil does 85141 have?

The USDA soil survey maps Pinamt at the center of ZIP 85141: very gravelly loam, well drained, pH about 8.2 (alkaline).

Did spring come early in Picacho, AZ in 2026?

Spring leaf-out near 85141 came on Jan 26 in 2026, about the same as the 1991–2020 average (Jan 25), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Picacho, AZ?

Short-day onions: the longest day near 85141 is 14 h 18 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.