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

Planting zone for 85705 — Tucson, AZ

ZIP code 85705 (Tucson, Pima County) is in USDA zone 9b: the coldest winter night averages 25 to 30 °F. The median last spring frost is February 11 and the first fall frost December 2.

Where ZIP 85705 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 11
First frostDec 2
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 11median — 50% chance of a later frost
Safe for tender plantsMarch 7only 10% chance of frost after
First fall frostDecember 2median — 10% chance by Nov 16
Growing season293 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 18 and returns around December 15.

From the NOAA station Tucson U Of A #1, AZ — within 1 mile, elevation 2,316 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 85705

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Dec 31 – Jan 14
SpinachSow outdoors · Dec 31 – Jan 21
Broccoli, cabbageStart indoors · Dec 3 – Dec 17
Broccoli, cabbageTransplant · Jan 21 – Feb 4
Onion setsPlant outdoors · Jan 14 – Jan 28
PotatoesPlant outdoors · Jan 21 – Feb 4
LettuceSow outdoors · Jan 14 – Jan 28
Carrots, beetsSow outdoors · Jan 21 – Feb 4
TomatoesStart indoors · Dec 17 – Dec 31
TomatoesTransplant · Feb 18 – Mar 4
Peppers, eggplantStart indoors · Dec 3 – Dec 17
Peppers, eggplantTransplant · Feb 25 – Mar 11
BeansSow outdoors · Feb 18 – Mar 4
Sweet cornSow outdoors · Feb 18 – Mar 4
Cucumbers, squashSow outdoors · Feb 18 – Mar 4
Fall lettuce, spinachSow outdoors · Oct 7 – Oct 21
GarlicPlant cloves · Nov 18 – Dec 23
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 11) and first fall frost (Dec 2) 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 85705 came on Jan 23 — 3 days earlier than the 1991–2020 average (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 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 85705 is Mohave — 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 groupCwater soaks in slowly
Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Mohave sandy loam, 0 to 1 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 85705; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Tucson, AZ

Summer high102 °Faverage high, June
Winter low39 °Faverage low, January
Hot days167days a year at 90 °F or more
Freezing nights21nights a year at 32 °F or less
Growing degree days7,536base 50 °F — the season’s usable heat
Longest day14 h 16 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
Precipitation10.4 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 39 °F 67°39° JanFebruary: average high 71 °F, low 42 °F 71°42° FebMarch: average high 77 °F, low 46 °F 77°46° MarApril: average high 84 °F, low 51 °F 84°51° AprMay: average high 93 °F, low 60 °F 93°60° MayJune: average high 102 °F, low 69 °F 102°69° JunJuly: average high 101 °F, low 75 °F 101°75° JulAugust: average high 100 °F, low 74 °F 100°74° AugSeptember: average high 96 °F, low 69 °F 96°69° SepOctober: average high 87 °F, low 57 °F 87°57° OctNovember: average high 76 °F, low 45 °F 76°45° NovDecember: average high 67 °F, low 39 °F 67°39° Dec

Precipitation by month inches

0″1″2″January: 1.01 in precipitation 1.0 JanFebruary: 1.03 in precipitation 1.0 FebMarch: 0.55 in precipitation 0.6 MarApril: 0.21 in precipitation 0.2 AprMay: 0.03 in precipitation 0.0 MayJune: 0.26 in precipitation 0.3 JunJuly: 1.98 in precipitation 2.0 JulAugust: 1.73 in precipitation 1.7 AugSeptember: 1.15 in precipitation 1.1 SepOctober: 0.89 in precipitation 0.9 OctNovember: 0.63 in precipitation 0.6 NovDecember: 0.96 in precipitation 1.0 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Tucson U Of A #1, AZ (within 1 mile); precipitation: Tucson 8.0 Nw, AZ (within 1 mile). 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.

857199b
Tucson, AZ · 3 mi
857249b
Tucson, AZ · 3 mi
857019b
Tucson, AZ · 4 mi
857459b
Tucson, AZ · 4 mi
857169b
Tucson, AZ · 4 mi
857049a
Tucson, AZ · 5 mi
857189a
Tucson, AZ · 5 mi
857029b
Tucson, AZ · 5 mi

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

Questions about 85705

What planting zone is ZIP code 85705?

ZIP code 85705 (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 85705 is February 11; after March 7 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Tucson U Of A #1 station.

When is the first frost in Tucson, AZ?

The median first fall frost near 85705 is December 2, giving a median frost-free growing season of 293 days.

When should I plant tomatoes in 85705?

Start tomato seeds indoors around Dec 17 – Dec 31 and set transplants outside around Feb 18 – Mar 4, one to three weeks after the median last frost.

How much rain and snow does 85705 get?

About 10.4 inches of precipitation a year (NOAA 1991–2020 normals, Tucson 8.0 Nw station).

How hot do summers get in Tucson, AZ?

The average high peaks at 102 °F in June, with about 167 days a year at 90 °F or more.

What kind of soil does 85705 have?

The USDA soil survey maps Mohave at the center of ZIP 85705: sandy loam, well drained, pH about 7.6 (slightly alkaline).

Did spring come early in Tucson, AZ in 2026?

Spring leaf-out near 85705 came on Jan 23 in 2026, 3 days earlier than the 1991–2020 average (Jan 26), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Tucson, AZ?

Short-day onions: the longest day near 85705 is 14 h 16 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.

Did the zone for 85705 change?

Yes. The 2012 USDA map put 85705 in zone 9a; the 2023 map puts it in zone 9b. The newer map uses 1991–2020 data and more weather stations.