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

Planting zone for 85636 — Sierra Vista, AZ

ZIP code 85636 (Sierra Vista, Cochise County) is in USDA zone 8b: the coldest winter night averages 15 to 20 °F. The median last spring frost is April 5 and the first fall frost November 9.

Where ZIP 85636 is

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.

Zone8b15 to 20 °F
Coldest night−9.4 to −6.7 °C
Last frostApr 5
First frostNov 9
2012 zone8b

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 8b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Sierra Vista, 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 Sierra Vista, AZ

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 5median — 50% chance of a later frost
Safe for tender plantsApril 21only 10% chance of frost after
First fall frostNovember 9median — 10% chance by Oct 23
Growing season216 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 15 and returns around November 21.

From the NOAA station Sierra Vista, AZ — 9 miles away, elevation 4,607 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 85636

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 22 – Mar 8
SpinachSow outdoors · Feb 22 – Mar 15
Broccoli, cabbageStart indoors · Jan 25 – Feb 8
Broccoli, cabbageTransplant · Mar 15 – Mar 29
Onion setsPlant outdoors · Mar 8 – Mar 22
PotatoesPlant outdoors · Mar 15 – Mar 29
LettuceSow outdoors · Mar 8 – Mar 22
Carrots, beetsSow outdoors · Mar 15 – Mar 29
TomatoesStart indoors · Feb 8 – Feb 22
TomatoesTransplant · Apr 12 – Apr 26
Peppers, eggplantStart indoors · Jan 25 – Feb 8
Peppers, eggplantTransplant · Apr 19 – May 3
BeansSow outdoors · Apr 12 – Apr 26
Sweet cornSow outdoors · Apr 12 – Apr 26
Cucumbers, squashSow outdoors · Apr 12 – Apr 26
Fall lettuce, spinachSow outdoors · Sep 14 – Sep 28
GarlicPlant cloves · Oct 26 – Nov 30
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 5) and first fall frost (Nov 9) 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 85636 came on Jan 31 — about the same time as the 1991–2020 average (Feb 1).

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 8b in Arizona

482 plants native to the lower 48 states, recorded in Arizona, and rated by the USDA to survive 15 °F or colder — the bottom of zone 8b. Each links to its USDA PLANTS profile.

Trees 25

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 105

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 196

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 147

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 Sierra Vista, AZ.

Soil in Sierra Vista, AZ

The soil mapped at the center of ZIP 85636 is Brookline — fine sandy loam, somewhat poorly drained.

TextureFine sandy loamdrains and warms fast; dries out and needs more feeding
pH7.9alkaline; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter1%low — add compost
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Brookline-Fluvaquents-Riverwash complex, 0 to 3 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 85636; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Sierra Vista, AZ

Summer high94 °Faverage high, June
Winter low30 °Faverage low, January
Hot days87days a year at 90 °F or more
Freezing nights45nights a year at 32 °F or less
Growing degree days4,768base 50 °F — the season’s usable heat
Longest day14 h 13 mindaylight on June 21
Shortest day10 h 05 mindaylight on December 21
Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb
Precipitation15.1 inper year, rain and melted snow

Average high and low, by month

20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 61 °F, low 30 °F 61°30° JanFebruary: average high 64 °F, low 33 °F 64°33° FebMarch: average high 71 °F, low 38 °F 71°38° MarApril: average high 78 °F, low 43 °F 78°43° AprMay: average high 85 °F, low 50 °F 85°50° MayJune: average high 94 °F, low 60 °F 94°60° JunJuly: average high 92 °F, low 63 °F 92°63° JulAugust: average high 90 °F, low 62 °F 90°62° AugSeptember: average high 87 °F, low 57 °F 87°57° SepOctober: average high 80 °F, low 47 °F 80°47° OctNovember: average high 70 °F, low 37 °F 70°37° NovDecember: average high 62 °F, low 30 °F 62°30° Dec

Precipitation by month inches

0″1″2″3″4″January: 0.93 in precipitation 0.9 JanFebruary: 0.92 in precipitation 0.9 FebMarch: 0.67 in precipitation 0.7 MarApril: 0.24 in precipitation 0.2 AprMay: 0.21 in precipitation 0.2 MayJune: 0.51 in precipitation 0.5 JunJuly: 3.46 in precipitation 3.5 JulAugust: 3.87 in precipitation 3.9 AugSeptember: 1.78 in precipitation 1.8 SepOctober: 0.85 in precipitation 0.8 OctNovember: 0.63 in precipitation 0.6 NovDecember: 1.05 in precipitation 1.1 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Sierra Vista, AZ (9 mi away); precipitation: Whetstone 2.6 Sw, AZ (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

856168b
Huachuca City, AZ · 3 mi
856718b
Sierra Vista, AZ · 8 mi
856358b
Sierra Vista, AZ · 10 mi
856138b
Fort Huachuca, AZ · 12 mi
856508b
Sierra Vista, AZ · 13 mi
856388b
Tombstone, AZ · 13 mi
856118a
Elgin, AZ · 14 mi
856308b
Saint David, AZ · 16 mi

All 4 ZIP codes in Sierra Vista → · Arizona planting zones →

Questions about 85636

What planting zone is ZIP code 85636?

ZIP code 85636 (Sierra Vista, AZ) is in USDA hardiness zone 8b on the 2023 map: the coldest night of an average winter reaches 15 to 20 °F (−9.4 to −6.7 °C).

When is the last frost in Sierra Vista, AZ?

The median last spring frost (32 °F) near 85636 is April 5; after April 21 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Sierra Vista station.

When is the first frost in Sierra Vista, AZ?

The median first fall frost near 85636 is November 9, giving a median frost-free growing season of 216 days.

When should I plant tomatoes in 85636?

Start tomato seeds indoors around Feb 8 – Feb 22 and set transplants outside around Apr 12 – Apr 26, one to three weeks after the median last frost.

How much rain and snow does 85636 get?

About 15.1 inches of precipitation a year (NOAA 1991–2020 normals, Whetstone 2.6 Sw station).

How hot do summers get in Sierra Vista, AZ?

The average high peaks at 94 °F in June, with about 87 days a year at 90 °F or more.

What kind of soil does 85636 have?

The USDA soil survey maps Brookline at the center of ZIP 85636: fine sandy loam, somewhat poorly drained, pH about 7.9 (alkaline).

Did spring come early in Sierra Vista, AZ in 2026?

Spring leaf-out near 85636 came on Jan 31 in 2026, about the same as the 1991–2020 average (Feb 1), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Sierra Vista, AZ?

Short-day onions: the longest day near 85636 is 14 h 13 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.