Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 86038 — Mormon Lake, AZ

ZIP code 86038 (Mormon Lake, Coconino County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is June 10 and the first fall frost September 27.

Where ZIP 86038 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.

Zone6b−5 to 0 °F

Coldest night−20.6 to −17.8 °C

Last frostJun 10

First frostSep 27

2012 zone6a

Was 6a 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 6b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Mormon Lake, 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 Mormon Lake, AZ

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostJune 10median — 50% chance of a later frost

Safe for tender plantsJune 27only 10% chance of frost after

First fall frostSeptember 27median — 10% chance by Sep 14

Growing season106 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 26 and returns around October 7.

From the NOAA station Mund'S Park, AZ — 9 miles away, elevation 6,470 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 86038

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 29 – May 13

SpinachSow outdoors · Apr 29 – May 20

Broccoli, cabbageStart indoors · Apr 1 – Apr 15

Broccoli, cabbageTransplant · May 20 – Jun 3

Onion setsPlant outdoors · May 13 – May 27

PotatoesPlant outdoors · May 20 – Jun 3

LettuceSow outdoors · May 13 – May 27

Carrots, beetsSow outdoors · May 20 – Jun 3

TomatoesStart indoors · Apr 15 – Apr 29

TomatoesTransplant · Jun 17 – Jul 1

Peppers, eggplantStart indoors · Apr 1 – Apr 15

Peppers, eggplantTransplant · Jun 24 – Jul 8

BeansSow outdoors · Jun 17 – Jul 1

Sweet cornSow outdoors · Jun 17 – Jul 1

Cucumbers, squashSow outdoors · Jun 17 – Jul 1

Fall lettuce, spinachSow outdoors · Aug 2 – Aug 16

GarlicPlant cloves · Sep 13 – Oct 18

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jun 10) and first fall frost (Sep 27) 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 86038 came on Mar 12 — 28 days earlier than the 1991–2020 average (Apr 9).

average
Apr 92026
Mar 12

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 6b in Arizona

441 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 6b. 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 Mormon Lake, AZ.

Soil in Mormon Lake, AZ

The soil mapped at the center of ZIP 86038 is Pachic Argiustolls — cobbly silt loam, well drained.

TextureCobbly silt loama good balance for most vegetables

pH5.8moderately acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter2%moderate

Hydrologic groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Pachic Argiustolls, Typic Haplustalfs, and Lithic Haplustepts; cool mesic ustic mountains.

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 86038; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Mormon Lake, AZ

Summer high83 °Faverage high, July

Winter low16 °Faverage low, December

Hot days4days a year at 90 °F or more

Freezing nights213nights a year at 32 °F or less

Growing degree days1,689base 50 °F — the season’s usable heat

Longest day14 h 30 mindaylight on June 21

Shortest day9 h 48 mindaylight on December 21

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

Precipitation28 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Mund'S Park, AZ (9 mi away); precipitation: Mormon Mountain, AZ (2 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.

860177a

Munds Park, AZ · 11 mi

860056a

Flagstaff, AZ · 14 mi

Flagstaff, AZ · 22 mi

Arizona planting zones →

Questions about 86038

What planting zone is ZIP code 86038?

ZIP code 86038 (Mormon Lake, AZ) is in USDA hardiness zone 6b on the 2023 map: the coldest night of an average winter reaches −5 to 0 °F (−20.6 to −17.8 °C).

When is the last frost in Mormon Lake, AZ?

The median last spring frost (32 °F) near 86038 is June 10; after June 27 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Mund'S Park station.

When is the first frost in Mormon Lake, AZ?

The median first fall frost near 86038 is September 27, giving a median frost-free growing season of 106 days.

When should I plant tomatoes in 86038?

Start tomato seeds indoors around Apr 15 – Apr 29 and set transplants outside around Jun 17 – Jul 1, one to three weeks after the median last frost.

How much rain and snow does 86038 get?

About 28 inches of precipitation a year (NOAA 1991–2020 normals, Mormon Mountain station).

How hot do summers get in Mormon Lake, AZ?

The average high peaks at 83 °F in July, with about 4 days a year at 90 °F or more.

What kind of soil does 86038 have?

The USDA soil survey maps Pachic Argiustolls at the center of ZIP 86038: cobbly silt loam, well drained, pH about 5.8 (moderately acidic).

Did spring come early in Mormon Lake, AZ in 2026?

Spring leaf-out near 86038 came on Mar 12 in 2026, 28 days earlier than the 1991–2020 average (Apr 9), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Mormon Lake, AZ?

Intermediate onions: the longest day near 86038 is 14 h 30 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 86038 change?

Yes. The 2012 USDA map put 86038 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.