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

Planting zone for 71731 — El Dorado, AR

ZIP code 71731 (El Dorado, Union County) is in USDA zone 8b: the coldest winter night averages 15 to 20 °F. The median last spring frost is March 24 and the first fall frost November 7.

Where ZIP 71731 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 frostMar 24

First frostNov 7

2012 zone8a

Was 8a 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 8b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for El Dorado, AR…

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 El Dorado, AR

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMarch 24median — 50% chance of a later frost

Safe for tender plantsApril 9only 10% chance of frost after

First fall frostNovember 7median — 10% chance by Oct 24

Growing season230 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 9 and returns around November 20.

From the NOAA station El Dorado S Ar Regional Airport, AR — 9 miles away, elevation 253 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 71731

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 10 – Feb 24

SpinachSow outdoors · Feb 10 – Mar 3

Broccoli, cabbageStart indoors · Jan 13 – Jan 27

Broccoli, cabbageTransplant · Mar 3 – Mar 17

Onion setsPlant outdoors · Feb 24 – Mar 10

PotatoesPlant outdoors · Mar 3 – Mar 17

LettuceSow outdoors · Feb 24 – Mar 10

Carrots, beetsSow outdoors · Mar 3 – Mar 17

TomatoesStart indoors · Jan 27 – Feb 10

TomatoesTransplant · Mar 31 – Apr 14

Peppers, eggplantStart indoors · Jan 13 – Jan 27

Peppers, eggplantTransplant · Apr 7 – Apr 21

BeansSow outdoors · Mar 31 – Apr 14

Sweet cornSow outdoors · Mar 31 – Apr 14

Cucumbers, squashSow outdoors · Mar 31 – Apr 14

Fall lettuce, spinachSow outdoors · Sep 12 – Sep 26

GarlicPlant cloves · Oct 24 – Nov 28

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 24) and first fall frost (Nov 7) 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 71731 came on Feb 11 — 4 days later than the 1991–2020 average (Feb 7).

average
Feb 72026
Feb 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 8b in Arkansas

521 plants native to the lower 48 states, recorded in Arkansas, and rated by the USDA to survive 15 °F or colder — the bottom of zone 8b. 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 El Dorado, AR.

Soil in El Dorado, AR

The soil mapped at the center of ZIP 71731 is Sacul — fine sandy loam, moderately well drained.

TextureFine sandy loamdrains and warms fast; dries out and needs more feeding

pH5.3strongly acidic; most vegetables like 6.0–7.0

DrainageModerately well drainednatural drainage class

Organic matter2%moderate

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Sacul fine sandy loam, 1 to 8 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 71731; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in El Dorado, AR

Summer high94 °Faverage high, July

Winter low34 °Faverage low, January

Hot days88days a year at 90 °F or more

Freezing nights53nights a year at 32 °F or less

Growing degree days5,854base 50 °F — the season’s usable heat

Longest day14 h 21 mindaylight on June 21

Shortest day9 h 57 mindaylight on December 21

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

Precipitation52.1 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: El Dorado S Ar Regional Airport, AR (9 mi away); precipitation: El Dorado S Ar Regional Airport, AR (9 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

Smackover, AR · 11 mi

717248b

Calion, AR · 12 mi

717498b

Junction City, AR · 13 mi

717518a

Louann, AR · 15 mi

717588b

Mount Holly, AR · 16 mi

All 2 ZIP codes in El Dorado → · Arkansas planting zones →

Questions about 71731

What planting zone is ZIP code 71731?

ZIP code 71731 (El Dorado, AR) 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 El Dorado, AR?

The median last spring frost (32 °F) near 71731 is March 24; after April 9 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, El Dorado S Ar Regional Airport station.

When is the first frost in El Dorado, AR?

The median first fall frost near 71731 is November 7, giving a median frost-free growing season of 230 days.

When should I plant tomatoes in 71731?

Start tomato seeds indoors around Jan 27 – Feb 10 and set transplants outside around Mar 31 – Apr 14, one to three weeks after the median last frost.

How much rain and snow does 71731 get?

About 52.1 inches of precipitation a year (NOAA 1991–2020 normals, El Dorado S Ar Regional Airport station).

How hot do summers get in El Dorado, AR?

The average high peaks at 94 °F in July, with about 88 days a year at 90 °F or more.

What kind of soil does 71731 have?

The USDA soil survey maps Sacul at the center of ZIP 71731: fine sandy loam, moderately well drained, pH about 5.3 (strongly acidic).

Did spring come early in El Dorado, AR in 2026?

Spring leaf-out near 71731 came on Feb 11 in 2026, 4 days later than the 1991–2020 average (Feb 7), according to the USA National Phenology Network Spring Index.

What kind of onions grow in El Dorado, AR?

Intermediate onions: the longest day near 71731 is 14 h 21 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 71731 change?

Yes. The 2012 USDA map put 71731 in zone 8a; the 2023 map puts it in zone 8b. The newer map uses 1991–2020 data and more weather stations.