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

Planting zone for 85709 — Tucson, AZ

ZIP code 85709 (Tucson, Pima County) is in USDA zone 9b: the coldest winter night averages 25 to 30 °F. The median last spring frost is February 5 and the first fall frost December 9.

Where ZIP 85709 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 frostFeb 5
First frostDec 9
2012 zone9a

Was 9a on the 2012 map — half a zone warmer now. 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 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 frostFebruary 5median — 50% chance of a later frost
Safe for tender plantsMarch 2only 10% chance of frost after
First fall frostDecember 9median — 10% chance by Nov 21
Growing season307 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 11 and returns around December 26.

From the NOAA station Tucson Intl Airport, AZ — 2 miles away, elevation 2,549 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 85709

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Dec 25 – Jan 8
SpinachSow outdoors · Dec 25 – Jan 15
Broccoli, cabbageStart indoors · Nov 27 – Dec 11
Broccoli, cabbageTransplant · Jan 15 – Jan 29
Onion setsPlant outdoors · Jan 8 – Jan 22
PotatoesPlant outdoors · Jan 15 – Jan 29
LettuceSow outdoors · Jan 8 – Jan 22
Carrots, beetsSow outdoors · Jan 15 – Jan 29
TomatoesStart indoors · Dec 11 – Dec 25
TomatoesTransplant · Feb 12 – Feb 26
Peppers, eggplantStart indoors · Nov 27 – Dec 11
Peppers, eggplantTransplant · Feb 19 – Mar 5
BeansSow outdoors · Feb 12 – Feb 26
Sweet cornSow outdoors · Feb 12 – Feb 26
Cucumbers, squashSow outdoors · Feb 12 – Feb 26
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 5) 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 85709 came on Jan 23 — about the same time as the 1991–2020 average (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 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.

Trees 26

Arizona cypress50 ft · blooms spring · low shade tolerance · to −23 °FArizona madrone30 ft · blooms late spring · high shade tolerance · to −4 °FArizona sycamore80 ft · blooms early spring · high shade tolerance · to −8 °FArizona walnut50 ft · blooms late spring · high shade tolerance · to −33 °Fblack locust60 ft · blooms spring · high shade tolerance · to −37 °Fblue spruce100 ft · blooms late spring · medium shade tolerance · to −38 °F

Shrubs 113

alderleaf mountain mahogany15 ft · blooms late spring · medium shade tolerance · to −41 °FAmerican plum24 ft · blooms mid spring · high shade tolerance · to −38 °FAmerican tarwort3 ft · blooms late spring · high shade tolerance · to −23 °Fantelope bitterbrush6 ft · blooms early spring · medium shade tolerance · to −36 °FApache plume6 ft · blooms late spring · high shade tolerance · to −23 °Fbig sagebrush4 ft · blooms mid summer · high shade tolerance · to −43 °F

Wildflowers & perennials 199

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °Falpine mountainsorrel1 ft · blooms mid summer · medium shade tolerance · to −43 °FAmerican alpine speedwell1 ft · blooms summer · medium shade tolerance · to −28 °FAmerican bistort1.5 ft · blooms mid spring · high shade tolerance · to −38 °FAmerican century plant6 ft · blooms indeterminate · high shade tolerance · to 12 °F

Grasses 152

alkali cordgrass3 ft · blooms late summer · high shade tolerance · to −38 °Falkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °Falpine timothy1.4 ft · blooms late spring · medium shade tolerance · to −43 °Fanalogue sedge1.5 ft · blooms late spring · medium shade tolerance · to −38 °FArizona cottontop4 ft · blooms late summer · high shade tolerance · to −13 °FArizona fescue2 ft · blooms late spring · high shade tolerance · to −23 °F

Vines 1

western white clematis1 ft · blooms mid summer · medium shade tolerance · to −38 °F

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 85709 is Rillito — sandy loam, well drained.

TextureSandy loamdrains and warms fast; dries out and needs more feeding
pH7.6slightly alkaline; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter0.75%low — add compost
Hydrologic groupBwater soaks in moderately
Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Rillito sandy loam, 1 to 3 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 85709; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Tucson, AZ

Summer high101 °Faverage high, June
Winter low41 °Faverage low, January
Hot days158days a year at 90 °F or more
Freezing nights12nights a year at 32 °F or less
Growing degree days7,673base 50 °F — the season’s usable heat
Longest day14 h 15 mindaylight on June 21
Shortest day10 h 02 mindaylight on December 21
Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb
Precipitation10.6 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°100°110°32 °FJanuary: average high 67 °F, low 41 °F 67°41° JanFebruary: average high 69 °F, low 43 °F 69°43° FebMarch: average high 76 °F, low 48 °F 76°48° MarApril: average high 83 °F, low 53 °F 83°53° AprMay: average high 92 °F, low 62 °F 92°62° MayJune: average high 101 °F, low 71 °F 101°71° JunJuly: average high 100 °F, low 76 °F 100°76° JulAugust: average high 99 °F, low 75 °F 99°75° AugSeptember: average high 95 °F, low 70 °F 95°70° SepOctober: average high 86 °F, low 59 °F 86°59° OctNovember: average high 75 °F, low 48 °F 75°48° NovDecember: average high 66 °F, low 41 °F 66°41° Dec

Precipitation by month inches

0″1″2″3″January: 0.84 in precipitation 0.8 JanFebruary: 0.84 in precipitation, 0.1 in snowfall 0.8 FebMarch: 0.56 in precipitation 0.6 MarApril: 0.24 in precipitation 0.2 AprMay: 0.20 in precipitation 0.2 MayJune: 0.23 in precipitation 0.2 JunJuly: 2.21 in precipitation 2.2 JulAugust: 1.98 in precipitation 2.0 AugSeptember: 1.32 in precipitation 1.3 SepOctober: 0.67 in precipitation 0.7 OctNovember: 0.56 in precipitation 0.6 NovDecember: 0.96 in precipitation 1.0 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Tucson Intl Airport, AZ (2 mi away); precipitation: Tucson Intl Airport, AZ (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 9b.

857239b
Tucson, AZ · 3 mi
857149b
Tucson, AZ · 3 mi
857069b
Tucson, AZ · 3 mi
857139b
Tucson, AZ · 4 mi
857269b
Tucson, AZ · 5 mi
857019b
Tucson, AZ · 5 mi
857079b
Tucson, AZ · 6 mi
857029b
Tucson, AZ · 7 mi

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

Questions about 85709

What planting zone is ZIP code 85709?

ZIP code 85709 (Tucson, 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 Tucson, AZ?

The median last spring frost (32 °F) near 85709 is February 5; after March 2 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Tucson Intl Airport station.

When is the first frost in Tucson, AZ?

The median first fall frost near 85709 is December 9, giving a median frost-free growing season of 307 days.

When should I plant tomatoes in 85709?

Start tomato seeds indoors around Dec 11 – Dec 25 and set transplants outside around Feb 12 – Feb 26, one to three weeks after the median last frost.

How much rain and snow does 85709 get?

About 10.6 inches of precipitation a year (NOAA 1991–2020 normals, Tucson Intl Airport station).

How hot do summers get in Tucson, AZ?

The average high peaks at 101 °F in June, with about 158 days a year at 90 °F or more.

What kind of soil does 85709 have?

The USDA soil survey maps Rillito at the center of ZIP 85709: sandy loam, well drained, pH about 7.6 (slightly alkaline).

Did spring come early in Tucson, AZ in 2026?

Spring leaf-out near 85709 came on Jan 23 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 Tucson, AZ?

Short-day onions: the longest day near 85709 is 14 h 15 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.

Did the zone for 85709 change?

Yes. The 2012 USDA map put 85709 in zone 9a; the 2023 map puts it in zone 9b. The newer map uses 1991–2020 data and more weather stations.