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

Planting zone for 85645 — Amado, AZ

ZIP code 85645 (Amado, Santa Cruz County) is in USDA zone 8b: the coldest winter night averages 15 to 20 °F. The median last spring frost is April 5 and the first fall frost November 10.

Where ZIP 85645 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.

Zone8b15 to 20 °F

Coldest night−9.4 to −6.7 °C

Last frostApr 5

First frostNov 10

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 Amado, 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 Amado, AZ

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 5median — 50% chance of a later frost

Safe for tender plantsApril 25only 10% chance of frost after

First fall frostNovember 10median — 10% chance by Oct 21

Growing season217 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 12 and returns around November 20.

From the NOAA station Tumacacori Nm, AZ — 11 miles away, elevation 3,268 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 85645

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 22 – Mar 8

SpinachSow outdoors · Feb 22 – Mar 15

Broccoli, cabbageStart indoors · Jan 25 – Feb 8

Broccoli, cabbageTransplant · Mar 15 – Mar 29

Onion setsPlant outdoors · Mar 8 – Mar 22

PotatoesPlant outdoors · Mar 15 – Mar 29

LettuceSow outdoors · Mar 8 – Mar 22

Carrots, beetsSow outdoors · Mar 15 – Mar 29

TomatoesStart indoors · Feb 8 – Feb 22

TomatoesTransplant · Apr 12 – Apr 26

Peppers, eggplantStart indoors · Jan 25 – Feb 8

Peppers, eggplantTransplant · Apr 19 – May 3

BeansSow outdoors · Apr 12 – Apr 26

Sweet cornSow outdoors · Apr 12 – Apr 26

Cucumbers, squashSow outdoors · Apr 12 – Apr 26

Fall lettuce, spinachSow outdoors · Sep 15 – Sep 29

GarlicPlant cloves · Oct 27 – Dec 1

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 5) and first fall frost (Nov 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 85645 came on Jan 25 — 5 days earlier than the 1991–2020 average (Jan 30).

average
Jan 302026
Jan 25

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.

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 Amado, AZ.

Soil in Amado, AZ

The soil mapped at the center of ZIP 85645 is Chiricahua — cobbly sandy loam, well drained.

TextureCobbly sandy loamdrains and warms fast; dries out and needs more feeding

pH6.8neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter1.25%low — add compost

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Chiricahua-Lampshire association, rolling.

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 85645; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Amado, AZ

Summer high95 °Faverage high, June

Winter low32 °Faverage low, January

Hot days115days a year at 90 °F or more

Freezing nights60nights a year at 32 °F or less

Growing degree days5,195base 50 °F — the season’s usable heat

Longest day14 h 13 mindaylight on June 21

Shortest day10 h 05 mindaylight on December 21

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

Precipitation16.4 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: Tumacacori Nm, AZ (11 mi away); precipitation: Tubac 2.9 Sw, AZ (8 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.

856468b

Tubac, AZ · 8 mi

856229a

Green Valley, AZ · 8 mi

856408b

Tumacacori, AZ · 11 mi

856018b

Arivaca, AZ · 14 mi

856149a

Green Valley, AZ · 15 mi

Arizona planting zones →

Questions about 85645

What planting zone is ZIP code 85645?

ZIP code 85645 (Amado, 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 Amado, AZ?

The median last spring frost (32 °F) near 85645 is April 5; after April 25 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Tumacacori Nm station.

When is the first frost in Amado, AZ?

The median first fall frost near 85645 is November 10, giving a median frost-free growing season of 217 days.

When should I plant tomatoes in 85645?

Start tomato seeds indoors around Feb 8 – Feb 22 and set transplants outside around Apr 12 – Apr 26, one to three weeks after the median last frost.

How much rain and snow does 85645 get?

About 16.4 inches of precipitation a year (NOAA 1991–2020 normals, Tubac 2.9 Sw station).

How hot do summers get in Amado, AZ?

The average high peaks at 95 °F in June, with about 115 days a year at 90 °F or more.

What kind of soil does 85645 have?

The USDA soil survey maps Chiricahua at the center of ZIP 85645: cobbly sandy loam, well drained, pH about 6.8 (neutral).

Did spring come early in Amado, AZ in 2026?

Spring leaf-out near 85645 came on Jan 25 in 2026, 5 days earlier than the 1991–2020 average (Jan 30), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Amado, AZ?

Short-day onions: the longest day near 85645 is 14 h 13 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.