Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 30, 2026

Planting zone for 86520 — Blue Gap, AZ

ZIP code 86520 (Blue Gap, Navajo County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is May 16 and the first fall frost October 10.

Where ZIP 86520 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.

Zone7a0 to 5 °F

Coldest night−17.8 to −15 °C

Last frostMay 16

First frostOct 10

2012 zone7a

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 7a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Blue Gap, 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 Blue Gap, AZ

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostMay 16median — 50% chance of a later frost

Safe for tender plantsJune 5only 10% chance of frost after

First fall frostOctober 10median — 10% chance by Sep 29

Growing season147 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 1 and returns around October 20.

From the NOAA station Keams Canyon, AZ — 20 miles away, elevation 6,204 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 86520

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 4 – Apr 18

SpinachSow outdoors · Apr 4 – Apr 25

Broccoli, cabbageStart indoors · Mar 7 – Mar 21

Broccoli, cabbageTransplant · Apr 25 – May 9

Onion setsPlant outdoors · Apr 18 – May 2

PotatoesPlant outdoors · Apr 25 – May 9

LettuceSow outdoors · Apr 18 – May 2

Carrots, beetsSow outdoors · Apr 25 – May 9

TomatoesStart indoors · Mar 21 – Apr 4

TomatoesTransplant · May 23 – Jun 6

Peppers, eggplantStart indoors · Mar 7 – Mar 21

Peppers, eggplantTransplant · May 30 – Jun 13

BeansSow outdoors · May 23 – Jun 6

Sweet cornSow outdoors · May 23 – Jun 6

Cucumbers, squashSow outdoors · May 23 – Jun 6

Fall lettuce, spinachSow outdoors · Aug 15 – Aug 29

GarlicPlant cloves · Sep 26 – Oct 31

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 16) and first fall frost (Oct 10) 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 86520 came on Mar 11 — 15 days earlier than the 1991–2020 average (Mar 26).

average
Mar 262026
Mar 11

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 7a in Arizona

457 plants native to the lower 48 states, recorded in Arizona, and rated by the USDA to survive 0 °F or colder — the bottom of zone 7a. Each links to its USDA PLANTS profile.

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 Blue Gap, AZ.

Soil in Blue Gap, AZ

The soil mapped at the center of ZIP 86520 is Ustic Torriorthents — very gravelly loam, well drained.

TextureVery gravelly loama good balance for most vegetables

pH8.2alkaline; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter0.8%low — add compost

Hydrologic groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Ustic Torriorthents-Rock outcrop complex, 2 to 65 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 86520; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Blue Gap, AZ

Summer high89 °Faverage high, July

Winter low17 °Faverage low, December

Hot days31days a year at 90 °F or more

Freezing nights172nights a year at 32 °F or less

Growing degree days2,647base 50 °F — the season’s usable heat

Longest day14 h 37 mindaylight on June 21

Shortest day9 h 42 mindaylight on December 21

Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully

Precipitation8.8 inper year, rain and melted snow

Snowfall5 inper year; 1 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Keams Canyon, AZ (20 mi away); precipitation: Canyon De Chelly, AZ (25 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.

Keams Canyon, AZ · 21 mi

Many Farms, AZ · 32 mi

865056b

Ganado, AZ · 33 mi

865116a

Saint Michaels, AZ · 40 mi

Arizona planting zones →

Questions about 86520

What planting zone is ZIP code 86520?

ZIP code 86520 (Blue Gap, AZ) is in USDA hardiness zone 7a on the 2023 map: the coldest night of an average winter reaches 0 to 5 °F (−17.8 to −15 °C).

When is the last frost in Blue Gap, AZ?

The median last spring frost (32 °F) near 86520 is May 16; after June 5 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Keams Canyon station.

When is the first frost in Blue Gap, AZ?

The median first fall frost near 86520 is October 10, giving a median frost-free growing season of 147 days.

When should I plant tomatoes in 86520?

Start tomato seeds indoors around Mar 21 – Apr 4 and set transplants outside around May 23 – Jun 6, one to three weeks after the median last frost.

How much rain and snow does 86520 get?

About 8.8 inches of precipitation a year and 5 inches of snowfall (NOAA 1991–2020 normals, Canyon De Chelly station).

How hot do summers get in Blue Gap, AZ?

The average high peaks at 89 °F in July, with about 31 days a year at 90 °F or more.

What kind of soil does 86520 have?

The USDA soil survey maps Ustic Torriorthents at the center of ZIP 86520: very gravelly loam, well drained, pH about 8.2 (alkaline).

Did spring come early in Blue Gap, AZ in 2026?

Spring leaf-out near 86520 came on Mar 11 in 2026, 15 days earlier than the 1991–2020 average (Mar 26), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Blue Gap, AZ?

Intermediate onions: the longest day near 86520 is 14 h 37 min, so day-neutral types bulb best; long-day varieties may not bulb fully.