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

Planting zone for 85346 — Quartzsite, AZ

ZIP code 85346 (Quartzsite, La Paz County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is January 28 and the first fall frost December 6.

Where ZIP 85346 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 frostJan 28
First frostDec 6
2012 zone9b

Was 9b 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 9a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Quartzsite, 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 Quartzsite, AZ

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostJanuary 28median — 50% chance of a later frost
Safe for tender plantsFebruary 24only 10% chance of frost after
First fall frostDecember 6median — 10% chance by Nov 22
Growing season315 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 7 and returns around December 21.

From the NOAA station Quartzsite, AZ — 6 miles away, elevation 876 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 85346

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Dec 17 – Dec 31
SpinachSow outdoors · Dec 17 – Jan 7
Broccoli, cabbageStart indoors · Nov 19 – Dec 3
Broccoli, cabbageTransplant · Jan 7 – Jan 21
Onion setsPlant outdoors · Dec 31 – Jan 14
PotatoesPlant outdoors · Jan 7 – Jan 21
LettuceSow outdoors · Dec 31 – Jan 14
Carrots, beetsSow outdoors · Jan 7 – Jan 21
TomatoesStart indoors · Dec 3 – Dec 17
TomatoesTransplant · Feb 4 – Feb 18
Peppers, eggplantStart indoors · Nov 19 – Dec 3
Peppers, eggplantTransplant · Feb 11 – Feb 25
BeansSow outdoors · Feb 4 – Feb 18
Sweet cornSow outdoors · Feb 4 – Feb 18
Cucumbers, squashSow outdoors · Feb 4 – Feb 18
Fall lettuce, spinachSow outdoors · Oct 11 – Oct 25
GarlicPlant cloves · Nov 22 – Dec 27
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jan 28) and first fall frost (Dec 6) 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 85346 came on Jan 22 — 4 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 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.

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 109

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 197

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 151

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 Quartzsite, AZ.

Soil in Quartzsite, AZ

The soil mapped at the center of ZIP 85346 is Gunsight — very gravelly sandy loam, somewhat excessively drained.

TextureVery gravelly sandy loamdrains and warms fast; dries out and needs more feeding
pH8.0alkaline; most vegetables like 6.0–7.0
DrainageSomewhat excessively drainednatural drainage class
Organic matter0.3%low — add compost
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Gunsight very gravelly sandy loam, dry, 1 to 8 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 85346; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Quartzsite, AZ

Summer high109 °Faverage high, July
Winter low39 °Faverage low, December
Hot days176days a year at 90 °F or more
Freezing nights12nights a year at 32 °F or less
Growing degree days8,760base 50 °F — the season’s usable heat
Longest day14 h 23 mindaylight on June 21
Shortest day9 h 55 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation4.6 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°100°110°120°32 °FJanuary: average high 67 °F, low 40 °F 67°40° JanFebruary: average high 71 °F, low 44 °F 71°44° FebMarch: average high 79 °F, low 51 °F 79°51° MarApril: average high 87 °F, low 57 °F 87°57° AprMay: average high 95 °F, low 66 °F 95°66° MayJune: average high 105 °F, low 75 °F 105°75° JunJuly: average high 109 °F, low 82 °F 109°82° JulAugust: average high 108 °F, low 82 °F 108°82° AugSeptember: average high 102 °F, low 74 °F 102°74° SepOctober: average high 90 °F, low 60 °F 90°60° OctNovember: average high 76 °F, low 47 °F 76°47° NovDecember: average high 65 °F, low 39 °F 65°39° Dec

Precipitation by month inches

0″1″January: 0.66 in precipitation, 0.2 in snowfall 0.7 JanFebruary: 0.65 in precipitation 0.7 FebMarch: 0.45 in precipitation 0.5 MarApril: 0.13 in precipitation 0.1 AprMay: 0.13 in precipitation 0.1 MayJune: 0.05 in precipitation 0.1 JunJuly: 0.47 in precipitation 0.5 JulAugust: 0.51 in precipitation 0.5 AugSeptember: 0.46 in precipitation 0.5 SepOctober: 0.23 in precipitation 0.2 OctNovember: 0.28 in precipitation 0.3 NovDecember: 0.56 in precipitation 0.6 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Quartzsite, AZ (6 mi away); precipitation: Quartzsite, AZ (6 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.

853599b
Quartzsite, AZ · 6 mi
853349b
Ehrenberg, AZ · 12 mi
853449b
Parker, AZ · 22 mi
853719a
Poston, AZ · 28 mi
922269b
Blythe, CA · 28 mi
853489a
Salome, AZ · 29 mi
853259a
Bouse, AZ · 29 mi
922259b
Blythe, CA · 30 mi

All 2 ZIP codes in Quartzsite → · Arizona planting zones →

Questions about 85346

What planting zone is ZIP code 85346?

ZIP code 85346 (Quartzsite, 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 Quartzsite, AZ?

The median last spring frost (32 °F) near 85346 is January 28; after February 24 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Quartzsite station.

When is the first frost in Quartzsite, AZ?

The median first fall frost near 85346 is December 6, giving a median frost-free growing season of 315 days.

When should I plant tomatoes in 85346?

Start tomato seeds indoors around Dec 3 – Dec 17 and set transplants outside around Feb 4 – Feb 18, one to three weeks after the median last frost.

How much rain and snow does 85346 get?

About 4.6 inches of precipitation a year (NOAA 1991–2020 normals, Quartzsite station).

How hot do summers get in Quartzsite, AZ?

The average high peaks at 109 °F in July, with about 176 days a year at 90 °F or more.

What kind of soil does 85346 have?

The USDA soil survey maps Gunsight at the center of ZIP 85346: very gravelly sandy loam, somewhat excessively drained, pH about 8.0 (alkaline).

Did spring come early in Quartzsite, AZ in 2026?

Spring leaf-out near 85346 came on Jan 22 in 2026, 4 days earlier than the 1991–2020 average (Jan 26), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Quartzsite, AZ?

Intermediate onions: the longest day near 85346 is 14 h 23 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 85346 change?

Yes. The 2012 USDA map put 85346 in zone 9b; the 2023 map puts it in zone 9a. The newer map uses 1991–2020 data and more weather stations.