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

Planting zone for 85629 — Sahuarita, AZ

ZIP code 85629 (Sahuarita, Pima County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is February 25 and the first fall frost November 27.

Where ZIP 85629 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 25

First frostNov 27

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 Sahuarita, 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 Sahuarita, AZ

JanFebMarAprMayJunJulAugSepOctNovDec

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

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

Safe for tender plantsMarch 18only 10% chance of frost after

First fall frostNovember 27median — 10% chance by Nov 12

Growing season276 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 1 and returns around December 10.

From the NOAA station Green Valley, AZ — 8 miles away, elevation 2,900 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 85629

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Jan 14 – Jan 28

SpinachSow outdoors · Jan 14 – Feb 4

Broccoli, cabbageStart indoors · Dec 17 – Dec 31

Broccoli, cabbageTransplant · Feb 4 – Feb 18

Onion setsPlant outdoors · Jan 28 – Feb 11

PotatoesPlant outdoors · Feb 4 – Feb 18

LettuceSow outdoors · Jan 28 – Feb 11

Carrots, beetsSow outdoors · Feb 4 – Feb 18

TomatoesStart indoors · Dec 31 – Jan 14

TomatoesTransplant · Mar 4 – Mar 18

Peppers, eggplantStart indoors · Dec 17 – Dec 31

Peppers, eggplantTransplant · Mar 11 – Mar 25

BeansSow outdoors · Mar 4 – Mar 18

Sweet cornSow outdoors · Mar 4 – Mar 18

Cucumbers, squashSow outdoors · Mar 4 – Mar 18

Fall lettuce, spinachSow outdoors · Oct 2 – Oct 16

GarlicPlant cloves · Nov 13 – Dec 18

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 25) and first fall frost (Nov 27) 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 85629 came on Jan 23 — 4 days earlier than the 1991–2020 average (Jan 27).

average
Jan 272026
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 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 Sahuarita, AZ.

Soil in Sahuarita, AZ

The soil mapped at the center of ZIP 85629 is Oracle — very gravelly loam, well drained.

TextureVery gravelly loama good balance for most vegetables

pH7.3neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter1.5%low — add compost

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Oracle-Romero-Rock outcrop complex, 5 to 35 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 85629; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Sahuarita, AZ

Summer high100 °Faverage high, June

Winter low36 °Faverage low, January

Hot days151days a year at 90 °F or more

Freezing nights24nights a year at 32 °F or less

Growing degree days6,939base 50 °F — the season’s usable heat

Longest day14 h 14 mindaylight on June 21

Shortest day10 h 03 mindaylight on December 21

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

Precipitation11.9 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: Green Valley, AZ (8 mi away); precipitation: Sahuarita 2.6 Wnw, AZ (7 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.

857469a

Tucson, AZ · 8 mi

856229a

Green Valley, AZ · 11 mi

Green Valley, AZ · 15 mi

Arizona planting zones →

Questions about 85629

What planting zone is ZIP code 85629?

ZIP code 85629 (Sahuarita, 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 Sahuarita, AZ?

The median last spring frost (32 °F) near 85629 is February 25; after March 18 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Green Valley station.

When is the first frost in Sahuarita, AZ?

The median first fall frost near 85629 is November 27, giving a median frost-free growing season of 276 days.

When should I plant tomatoes in 85629?

Start tomato seeds indoors around Dec 31 – Jan 14 and set transplants outside around Mar 4 – Mar 18, one to three weeks after the median last frost.

How much rain and snow does 85629 get?

About 11.9 inches of precipitation a year (NOAA 1991–2020 normals, Sahuarita 2.6 Wnw station).

How hot do summers get in Sahuarita, AZ?

The average high peaks at 100 °F in June, with about 151 days a year at 90 °F or more.

What kind of soil does 85629 have?

The USDA soil survey maps Oracle at the center of ZIP 85629: very gravelly loam, well drained, pH about 7.3 (neutral).

Did spring come early in Sahuarita, AZ in 2026?

Spring leaf-out near 85629 came on Jan 23 in 2026, 4 days earlier than the 1991–2020 average (Jan 27), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Sahuarita, AZ?

Short-day onions: the longest day near 85629 is 14 h 14 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.