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

Planting zone for Fountain Hills, AZ

Fountain Hills, AZ is in USDA zone 9b across its 2 ZIP codes.

Fountain Hills on the zone map

Outlined: its 1 ZIP code areas · 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
ZIP codes2
Last frostrare
First frostrare
Growing seasonall year

9b 2 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Fountain Hills, 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

A 32 °F frost doesn't happen here in most winters. At the nearest station (NOAA station Fountain Hills, AZ, elevation 1,581 ft) the median growing season is 356 days. When frost does come, it is a midwinter night or two; cover tender plants when a freeze is forecast.

Frost data: NOAA NCEI U.S. Climate Normals 1991–2020.

When spring arrived in 2026

In 2026, spring leaf-out near 85269 came on Jan 21 — 3 days earlier than the 1991–2020 average (Jan 24).

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 Fountain Hills, AZ.

Soil in Fountain Hills, AZ

The soil mapped at the center of ZIP 85269 is Eba — very gravelly loam, well drained.

TextureVery gravelly loama good balance for most vegetables
pH7.5slightly alkaline; 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: Eba-Pinaleno complex, 3 to 20 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 85269; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Fountain Hills, AZ

Summer high103 °Faverage high, July
Winter low44 °Faverage low, December
Hot days167days a year at 90 °F or more
Freezing nights4nights a year at 32 °F or less
Growing degree days8,179base 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
Precipitation10.2 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 64 °F, low 45 °F 64°45° JanFebruary: average high 67 °F, low 46 °F 67°46° FebMarch: average high 74 °F, low 51 °F 74°51° MarApril: average high 82 °F, low 56 °F 82°56° AprMay: average high 91 °F, low 65 °F 91°65° MayJune: average high 101 °F, low 73 °F 101°73° JunJuly: average high 103 °F, low 80 °F 103°80° JulAugust: average high 102 °F, low 80 °F 102°80° AugSeptember: average high 97 °F, low 74 °F 97°74° SepOctober: average high 87 °F, low 63 °F 87°63° OctNovember: average high 74 °F, low 51 °F 74°51° NovDecember: average high 63 °F, low 44 °F 63°44° Dec

Precipitation by month inches

0″1″2″January: 1.41 in precipitation 1.4 JanFebruary: 1.33 in precipitation 1.3 FebMarch: 1.28 in precipitation 1.3 MarApril: 0.33 in precipitation 0.3 AprMay: 0.23 in precipitation 0.2 MayJune: 0.14 in precipitation 0.1 JunJuly: 0.80 in precipitation 0.8 JulAugust: 1.33 in precipitation 1.3 AugSeptember: 0.81 in precipitation 0.8 SepOctober: 0.63 in precipitation 0.6 OctNovember: 0.74 in precipitation 0.7 NovDecember: 1.15 in precipitation 1.1 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Fountain Hills, AZ (within 1 mile); precipitation: Fountain Hills, AZ (within 1 mile). Daylight is calculated from latitude.

ZIP codes in Fountain Hills

852689b
25 to 30 °F
852699b
25 to 30 °F

Arizona planting zones →

Questions about Fountain Hills

What planting zone is Fountain Hills, AZ?

Fountain Hills, AZ is in USDA hardiness zone 9b on the 2023 map (9b: 25 to 30 °F).

What kind of onions grow in Fountain Hills, AZ?

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

How much rain and snow does Fountain Hills, AZ get?

About 10.2 inches of precipitation a year (NOAA 1991–2020 normals).