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

Planting zone for 85940 — Vernon, AZ

ZIP code 85940 (Vernon, Apache County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is May 20 and the first fall frost October 11.

Where ZIP 85940 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 frostMay 20

First frostOct 11

2012 zone6b

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 6b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Vernon, 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 Vernon, AZ

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 20median — 50% chance of a later frost

Safe for tender plantsJune 4only 10% chance of frost after

First fall frostOctober 11median — 10% chance by Sep 29

Growing season142 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 6 and returns around October 22.

From the NOAA station Mc Nary 2n, AZ — 13 miles away, elevation 7,340 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 85940

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 8 – Apr 22

SpinachSow outdoors · Apr 8 – Apr 29

Broccoli, cabbageStart indoors · Mar 11 – Mar 25

Broccoli, cabbageTransplant · Apr 29 – May 13

Onion setsPlant outdoors · Apr 22 – May 6

PotatoesPlant outdoors · Apr 29 – May 13

LettuceSow outdoors · Apr 22 – May 6

Carrots, beetsSow outdoors · Apr 29 – May 13

TomatoesStart indoors · Mar 25 – Apr 8

TomatoesTransplant · May 27 – Jun 10

Peppers, eggplantStart indoors · Mar 11 – Mar 25

Peppers, eggplantTransplant · Jun 3 – Jun 17

BeansSow outdoors · May 27 – Jun 10

Sweet cornSow outdoors · May 27 – Jun 10

Cucumbers, squashSow outdoors · May 27 – Jun 10

Fall lettuce, spinachSow outdoors · Aug 16 – Aug 30

GarlicPlant cloves · Sep 27 – Nov 1

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 20) and first fall frost (Oct 11) 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 85940 came on Mar 2 — 22 days earlier than the 1991–2020 average (Mar 24).

average
Mar 242026
Mar 2

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 Vernon, AZ.

Soil in Vernon, AZ

The soil mapped at the center of ZIP 85940 is Springerville — clay, well drained.

TextureClayholds water and nutrients; slow to drain and warm up

pH7.9alkaline; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter1.5%low — add compost

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Springerville clay.

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 85940; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Vernon, AZ

Summer high80 °Faverage high, June

Winter low21 °Faverage low, January

Hot days2days a year at 90 °F or more

Freezing nights170nights a year at 32 °F or less

Growing degree days1,900base 50 °F — the season’s usable heat

Longest day14 h 27 mindaylight on June 21

Shortest day9 h 52 mindaylight on December 21

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

Precipitation24.1 inper year, rain and melted snow

Snowfall66 inper year; 70 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: Mc Nary 2n, AZ (13 mi away); precipitation: Mc Nary 2n, AZ (13 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

White Mountain Lake, AZ · 16 mi

859386b

Springerville, AZ · 18 mi

Arizona planting zones →

Questions about 85940

What planting zone is ZIP code 85940?

ZIP code 85940 (Vernon, 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 Vernon, AZ?

The median last spring frost (32 °F) near 85940 is May 20; after June 4 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Mc Nary 2n station.

When is the first frost in Vernon, AZ?

The median first fall frost near 85940 is October 11, giving a median frost-free growing season of 142 days.

When should I plant tomatoes in 85940?

Start tomato seeds indoors around Mar 25 – Apr 8 and set transplants outside around May 27 – Jun 10, one to three weeks after the median last frost.

How much rain and snow does 85940 get?

About 24.1 inches of precipitation a year and 66 inches of snowfall (NOAA 1991–2020 normals, Mc Nary 2n station).

How hot do summers get in Vernon, AZ?

The average high peaks at 80 °F in June, with about 2 days a year at 90 °F or more.

What kind of soil does 85940 have?

The USDA soil survey maps Springerville at the center of ZIP 85940: clay, well drained, pH about 7.9 (alkaline).

Did spring come early in Vernon, AZ in 2026?

Spring leaf-out near 85940 came on Mar 2 in 2026, 22 days earlier than the 1991–2020 average (Mar 24), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Vernon, AZ?

Intermediate onions: the longest day near 85940 is 14 h 27 min, so day-neutral types bulb best; long-day varieties may not bulb fully.