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

Planting zone for 85611 — Elgin, AZ

ZIP code 85611 (Elgin, Santa Cruz County) is in USDA zone 8a: the coldest winter night averages 10 to 15 °F. The median last spring frost is April 18 and the first fall frost November 1.

Where ZIP 85611 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.

Zone8a10 to 15 °F
Coldest night−12.2 to −9.4 °C
Last frostApr 18
First frostNov 1
2012 zone8a

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 8a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Elgin, 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 Elgin, AZ

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 18median — 50% chance of a later frost
Safe for tender plantsMay 3only 10% chance of frost after
First fall frostNovember 1median — 10% chance by Oct 18
Growing season195 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 2 and returns around November 14.

From the NOAA station Elgin 5 S, AZ — 4 miles away, elevation 4,810 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 85611

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 7 – Mar 21
SpinachSow outdoors · Mar 7 – Mar 28
Broccoli, cabbageStart indoors · Feb 7 – Feb 21
Broccoli, cabbageTransplant · Mar 28 – Apr 11
Onion setsPlant outdoors · Mar 21 – Apr 4
PotatoesPlant outdoors · Mar 28 – Apr 11
LettuceSow outdoors · Mar 21 – Apr 4
Carrots, beetsSow outdoors · Mar 28 – Apr 11
TomatoesStart indoors · Feb 21 – Mar 7
TomatoesTransplant · Apr 25 – May 9
Peppers, eggplantStart indoors · Feb 7 – Feb 21
Peppers, eggplantTransplant · May 2 – May 16
BeansSow outdoors · Apr 25 – May 9
Sweet cornSow outdoors · Apr 25 – May 9
Cucumbers, squashSow outdoors · Apr 25 – May 9
Fall lettuce, spinachSow outdoors · Sep 6 – Sep 20
GarlicPlant cloves · Oct 18 – Nov 22
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 18) and first fall frost (Nov 1) 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 85611 came on Feb 1 — 4 days earlier than the 1991–2020 average (Feb 5).

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).

Soil in Elgin, AZ

The soil mapped at the center of ZIP 85611 is Pima — clay loam, well drained.

TextureClay loamholds 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 groupCwater soaks in slowly
Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Pima soils.

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 85611; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Elgin, AZ

Summer high92 °Faverage high, June
Winter low29 °Faverage low, January
Hot days60days a year at 90 °F or more
Freezing nights83nights a year at 32 °F or less
Growing degree days4,238base 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
Precipitation15.4 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 60 °F, low 29 °F 60°29° JanFebruary: average high 62 °F, low 31 °F 62°31° FebMarch: average high 68 °F, low 35 °F 68°35° MarApril: average high 75 °F, low 40 °F 75°40° AprMay: average high 83 °F, low 48 °F 83°48° MayJune: average high 92 °F, low 57 °F 92°57° JunJuly: average high 89 °F, low 63 °F 89°63° JulAugust: average high 87 °F, low 61 °F 87°61° AugSeptember: average high 85 °F, low 55 °F 85°55° SepOctober: average high 78 °F, low 45 °F 78°45° OctNovember: average high 68 °F, low 35 °F 68°35° NovDecember: average high 59 °F, low 29 °F 59°29° Dec

Precipitation by month inches

0″1″2″3″4″January: 1.19 in precipitation 1.2 JanFebruary: 1.03 in precipitation 1.0 FebMarch: 0.66 in precipitation 0.7 MarApril: 0.19 in precipitation 0.2 AprMay: 0.24 in precipitation 0.2 MayJune: 0.61 in precipitation 0.6 JunJuly: 3.88 in precipitation 3.9 JulAugust: 3.41 in precipitation 3.4 AugSeptember: 1.73 in precipitation 1.7 SepOctober: 0.77 in precipitation 0.8 OctNovember: 0.61 in precipitation 0.6 NovDecember: 1.05 in precipitation 1.1 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Elgin 5 S, AZ (4 mi away); precipitation: Elgin 5 S, AZ (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

856138b
Fort Huachuca, AZ · 9 mi
856378a
Sonoita, AZ · 12 mi
856168b
Huachuca City, AZ · 12 mi
856718b
Sierra Vista, AZ · 14 mi
856368b
Sierra Vista, AZ · 14 mi
856248a
Patagonia, AZ · 15 mi
856288b
Nogales, AZ · 25 mi
856149a
Green Valley, AZ · 27 mi

Arizona planting zones →

Questions about 85611

What planting zone is ZIP code 85611?

ZIP code 85611 (Elgin, AZ) is in USDA hardiness zone 8a on the 2023 map: the coldest night of an average winter reaches 10 to 15 °F (−12.2 to −9.4 °C).

When is the last frost in Elgin, AZ?

The median last spring frost (32 °F) near 85611 is April 18; after May 3 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Elgin 5 S station.

When is the first frost in Elgin, AZ?

The median first fall frost near 85611 is November 1, giving a median frost-free growing season of 195 days.

When should I plant tomatoes in 85611?

Start tomato seeds indoors around Feb 21 – Mar 7 and set transplants outside around Apr 25 – May 9, one to three weeks after the median last frost.

How much rain and snow does 85611 get?

About 15.4 inches of precipitation a year (NOAA 1991–2020 normals, Elgin 5 S station).

How hot do summers get in Elgin, AZ?

The average high peaks at 92 °F in June, with about 60 days a year at 90 °F or more.

What kind of soil does 85611 have?

The USDA soil survey maps Pima at the center of ZIP 85611: clay loam, well drained, pH about 7.9 (alkaline).

Did spring come early in Elgin, AZ in 2026?

Spring leaf-out near 85611 came on Feb 1 in 2026, 4 days earlier than the 1991–2020 average (Feb 5), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Elgin, AZ?

Short-day onions: the longest day near 85611 is 14 h 13 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.