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

Planting zone for 86021 — Colorado City, AZ

ZIP code 86021 (Colorado City, Mohave County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is April 26 and the first fall frost October 25.

Where ZIP 86021 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.

Zone7b5 to 10 °F
Coldest night−15 to −12.2 °C
Last frostApr 26
First frostOct 25
2012 zone7b

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 7b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Colorado City, 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 Colorado City, AZ

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 26median — 50% chance of a later frost
Safe for tender plantsMay 15only 10% chance of frost after
First fall frostOctober 25median — 10% chance by Oct 11
Growing season180 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 10 and returns around November 5.

From the NOAA station Colorado City, AZ — 11 miles away, elevation 5,000 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 86021

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 15 – Mar 29
SpinachSow outdoors · Mar 15 – Apr 5
Broccoli, cabbageStart indoors · Feb 15 – Mar 1
Broccoli, cabbageTransplant · Apr 5 – Apr 19
Onion setsPlant outdoors · Mar 29 – Apr 12
PotatoesPlant outdoors · Apr 5 – Apr 19
LettuceSow outdoors · Mar 29 – Apr 12
Carrots, beetsSow outdoors · Apr 5 – Apr 19
TomatoesStart indoors · Mar 1 – Mar 15
TomatoesTransplant · May 3 – May 17
Peppers, eggplantStart indoors · Feb 15 – Mar 1
Peppers, eggplantTransplant · May 10 – May 24
BeansSow outdoors · May 3 – May 17
Sweet cornSow outdoors · May 3 – May 17
Cucumbers, squashSow outdoors · May 3 – May 17
Fall lettuce, spinachSow outdoors · Aug 30 – Sep 13
GarlicPlant cloves · Oct 11 – Nov 15
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 26) and first fall frost (Oct 25) 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 86021 came on Feb 12 — 20 days earlier than the 1991–2020 average (Mar 4).

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 7b in Arizona

459 plants native to the lower 48 states, recorded in Arizona, and rated by the USDA to survive 5 °F or colder — the bottom of zone 7b. Each links to its USDA PLANTS profile.

Trees 24

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 95

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 190

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 eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °F

Grasses 142

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 Colorado City, AZ.

Soil in Colorado City, AZ

The soil mapped at the center of ZIP 86021 is Haplogypsids — gypsiferous silt loam, well drained.

TextureGypsiferous silt loama good balance for most vegetables
pH8.0alkaline; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter0.75%low — add compost
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Haplogypsids-Haplogypsids, shallow complex, 1 to 50 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 86021; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Colorado City, AZ

Summer high95 °Faverage high, July
Winter low24 °Faverage low, December
Hot days72days a year at 90 °F or more
Freezing nights120nights a year at 32 °F or less
Growing degree days3,812base 50 °F — the season’s usable heat
Longest day14 h 42 mindaylight on June 21
Shortest day9 h 37 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation14.3 inper year, rain and melted snow
Snowfall12 inper year; 9 days with snow on the ground

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°110°32 °FJanuary: average high 49 °F, low 25 °F 49°25° JanFebruary: average high 53 °F, low 28 °F 53°28° FebMarch: average high 61 °F, low 33 °F 61°33° MarApril: average high 68 °F, low 38 °F 68°38° AprMay: average high 78 °F, low 46 °F 78°46° MayJune: average high 89 °F, low 54 °F 89°54° JunJuly: average high 95 °F, low 62 °F 95°62° JulAugust: average high 92 °F, low 62 °F 92°62° AugSeptember: average high 85 °F, low 54 °F 85°54° SepOctober: average high 72 °F, low 42 °F 72°42° OctNovember: average high 59 °F, low 31 °F 59°31° NovDecember: average high 48 °F, low 24 °F 48°24° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″January: 1.33 in precipitation, 2.9 in snowfall 1.3❄3 JanFebruary: 1.81 in precipitation, 3.6 in snowfall 1.8❄4 FebMarch: 1.67 in precipitation, 1.1 in snowfall 1.7❄1 MarApril: 1.12 in precipitation, 0.6 in snowfall 1.1❄1 AprMay: 0.56 in precipitation 0.6 MayJune: 0.31 in precipitation 0.3 JunJuly: 1.22 in precipitation 1.2 JulAugust: 1.43 in precipitation 1.4 AugSeptember: 1.48 in precipitation 1.5 SepOctober: 1.16 in precipitation, 0.4 in snowfall 1.2 OctNovember: 1.10 in precipitation, 0.7 in snowfall 1.1❄1 NovDecember: 1.13 in precipitation, 3.1 in snowfall 1.1❄3 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Colorado City, AZ (11 mi away); precipitation: Colorado City, AZ (11 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

847378b
Hurricane, UT · 8 mi
847847a
Hildale, UT · 11 mi
847638a
Rockville, UT · 15 mi
847458a
La Verkin, UT · 20 mi
847676b
Springdale, UT · 20 mi
847748b
Toquerville, UT · 22 mi
847808b
Washington, UT · 22 mi
847468b
Leeds, UT · 24 mi

Arizona planting zones →

Questions about 86021

What planting zone is ZIP code 86021?

ZIP code 86021 (Colorado City, AZ) is in USDA hardiness zone 7b on the 2023 map: the coldest night of an average winter reaches 5 to 10 °F (−15 to −12.2 °C).

When is the last frost in Colorado City, AZ?

The median last spring frost (32 °F) near 86021 is April 26; after May 15 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Colorado City station.

When is the first frost in Colorado City, AZ?

The median first fall frost near 86021 is October 25, giving a median frost-free growing season of 180 days.

When should I plant tomatoes in 86021?

Start tomato seeds indoors around Mar 1 – Mar 15 and set transplants outside around May 3 – May 17, one to three weeks after the median last frost.

How much rain and snow does 86021 get?

About 14.3 inches of precipitation a year and 12 inches of snowfall (NOAA 1991–2020 normals, Colorado City station).

How hot do summers get in Colorado City, AZ?

The average high peaks at 95 °F in July, with about 72 days a year at 90 °F or more.

What kind of soil does 86021 have?

The USDA soil survey maps Haplogypsids at the center of ZIP 86021: gypsiferous silt loam, well drained, pH about 8.0 (alkaline).

Did spring come early in Colorado City, AZ in 2026?

Spring leaf-out near 86021 came on Feb 12 in 2026, 20 days earlier than the 1991–2020 average (Mar 4), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Colorado City, AZ?

Intermediate onions: the longest day near 86021 is 14 h 42 min, so day-neutral types bulb best; long-day varieties may not bulb fully.