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

Planting zone for 85736 — Tucson, AZ

ZIP code 85736 (Tucson, Pima County) is in USDA zone 8b: the coldest winter night averages 15 to 20 °F. The median last spring frost is March 27 and the first fall frost November 9.

Where ZIP 85736 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 frostMar 27

First frostNov 9

2012 zone9a

Was 9a on the 2012 map — half a zone colder now. 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 Tucson, 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 Tucson, AZ

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMarch 27median — 50% chance of a later frost

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

First fall frostNovember 9median — 10% chance by Oct 25

Growing season226 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 6 and returns around November 21.

From the NOAA station Anvil Rch, AZ — 7 miles away, elevation 2,759 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 85736

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 13 – Feb 27

SpinachSow outdoors · Feb 13 – Mar 6

Broccoli, cabbageStart indoors · Jan 16 – Jan 30

Broccoli, cabbageTransplant · Mar 6 – Mar 20

Onion setsPlant outdoors · Feb 27 – Mar 13

PotatoesPlant outdoors · Mar 6 – Mar 20

LettuceSow outdoors · Feb 27 – Mar 13

Carrots, beetsSow outdoors · Mar 6 – Mar 20

TomatoesStart indoors · Jan 30 – Feb 13

TomatoesTransplant · Apr 3 – Apr 17

Peppers, eggplantStart indoors · Jan 16 – Jan 30

Peppers, eggplantTransplant · Apr 10 – Apr 24

BeansSow outdoors · Apr 3 – Apr 17

Sweet cornSow outdoors · Apr 3 – Apr 17

Cucumbers, squashSow outdoors · Apr 3 – Apr 17

Fall lettuce, spinachSow outdoors · Sep 14 – Sep 28

GarlicPlant cloves · Oct 26 – Nov 30

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 27) and first fall frost (Nov 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 85736 came on Jan 25 — 3 days earlier than the 1991–2020 average (Jan 28).

average
Jan 282026
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 Tucson, AZ.

Soil in Tucson, AZ

The soil mapped at the center of ZIP 85736 is Pinaleno — very cobbly sandy loam, well drained.

TextureVery cobbly sandy loamdrains and warms fast; dries out and needs more feeding

pH7.2neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter0.75%low — add compost

Hydrologic groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Pinaleno-Stagecoach complex, 5 to 16 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 85736; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Tucson, AZ

Summer high99 °Faverage high, June

Winter low33 °Faverage low, December

Hot days147days a year at 90 °F or more

Freezing nights54nights a year at 32 °F or less

Growing degree days6,217base 50 °F — the season’s usable heat

Longest day14 h 14 mindaylight on June 21

Shortest day10 h 04 mindaylight on December 21

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

Precipitation19.9 inper year, rain and melted snow

Snowfall8 inper year; 4 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Anvil Rch, AZ (7 mi away); precipitation: Kitt Peak, AZ (15 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

857359a

Tucson, AZ · 16 mi

856299a

Sahuarita, AZ · 16 mi

856229a

Green Valley, AZ · 17 mi

All 53 ZIP codes in Tucson → · Arizona planting zones →

Questions about 85736

What planting zone is ZIP code 85736?

ZIP code 85736 (Tucson, 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 Tucson, AZ?

The median last spring frost (32 °F) near 85736 is March 27; after April 18 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Anvil Rch station.

When is the first frost in Tucson, AZ?

The median first fall frost near 85736 is November 9, giving a median frost-free growing season of 226 days.

When should I plant tomatoes in 85736?

Start tomato seeds indoors around Jan 30 – Feb 13 and set transplants outside around Apr 3 – Apr 17, one to three weeks after the median last frost.

How much rain and snow does 85736 get?

About 19.9 inches of precipitation a year and 8 inches of snowfall (NOAA 1991–2020 normals, Kitt Peak station).

How hot do summers get in Tucson, AZ?

The average high peaks at 99 °F in June, with about 147 days a year at 90 °F or more.

What kind of soil does 85736 have?

The USDA soil survey maps Pinaleno at the center of ZIP 85736: very cobbly sandy loam, well drained, pH about 7.2 (neutral).

Did spring come early in Tucson, AZ in 2026?

Spring leaf-out near 85736 came on Jan 25 in 2026, 3 days earlier than the 1991–2020 average (Jan 28), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Tucson, AZ?

Short-day onions: the longest day near 85736 is 14 h 14 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.

Did the zone for 85736 change?

Yes. The 2012 USDA map put 85736 in zone 9a; the 2023 map puts it in zone 8b. The newer map uses 1991–2020 data and more weather stations.