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

Planting zone for 57212 — Arlington, SD

ZIP code 57212 (Arlington, Kingsbury County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is May 3 and the first fall frost October 2.

Where ZIP 57212 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.

Zone4b−25 to −20 °F

Coldest night−31.7 to −28.9 °C

Last frostMay 3

First frostOct 2

2012 zone4b

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 4b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Arlington, SD…

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 Arlington, SD

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 3median — 50% chance of a later frost

Safe for tender plantsMay 15only 10% chance of frost after

First fall frostOctober 2median — 10% chance by Sep 19

Growing season151 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 25 and returns around October 10.

From the NOAA station Arlington 1 W, SD — 2 miles away, elevation 1,824 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 57212

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 22 – Apr 5

SpinachSow outdoors · Mar 22 – Apr 12

Broccoli, cabbageStart indoors · Feb 22 – Mar 8

Broccoli, cabbageTransplant · Apr 12 – Apr 26

Onion setsPlant outdoors · Apr 5 – Apr 19

PotatoesPlant outdoors · Apr 12 – Apr 26

LettuceSow outdoors · Apr 5 – Apr 19

Carrots, beetsSow outdoors · Apr 12 – Apr 26

TomatoesStart indoors · Mar 8 – Mar 22

TomatoesTransplant · May 10 – May 24

Peppers, eggplantStart indoors · Feb 22 – Mar 8

Peppers, eggplantTransplant · May 17 – May 31

BeansSow outdoors · May 10 – May 24

Sweet cornSow outdoors · May 10 – May 24

Cucumbers, squashSow outdoors · May 10 – May 24

Fall lettuce, spinachSow outdoors · Aug 7 – Aug 21

GarlicPlant cloves · Sep 18 – Oct 23

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 3) and first fall frost (Oct 2) 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 57212 came on Apr 3 — 14 days earlier than the 1991–2020 average (Apr 17).

average
Apr 172026
Apr 3

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 Arlington, SD

The soil mapped at the center of ZIP 57212 is Poinsett — silty clay loam, well drained.

TextureSilty clay loamholds water and nutrients; slow to drain and warm up

pH6.7neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter3%moderate

Hydrologic groupCwater soaks in slowly

Farmland classprime farmlandUSDA classification

Map unit: Poinsett-Buse-Waubay complex, 1 to 6 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 57212; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Arlington, SD

Summer high83 °Faverage high, July

Winter low5 °Faverage low, January

Hot days10days a year at 90 °F or more

Freezing nights166nights a year at 32 °F or less

Growing degree days2,585base 50 °F — the season’s usable heat

Longest day15 h 32 mindaylight on June 21

Shortest day8 h 50 mindaylight on December 21

Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)

Precipitation26.2 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: Arlington 1 W, SD (2 mi away); precipitation: Arlington 1 W, SD (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 4b.

Lake Preston, SD · 11 mi

572204b

Bruce, SD · 12 mi

572484b

Lake Norden, SD · 14 mi

South Dakota planting zones →

Questions about 57212

What planting zone is ZIP code 57212?

ZIP code 57212 (Arlington, SD) is in USDA hardiness zone 4b on the 2023 map: the coldest night of an average winter reaches −25 to −20 °F (−31.7 to −28.9 °C).

When is the last frost in Arlington, SD?

The median last spring frost (32 °F) near 57212 is May 3; after May 15 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Arlington 1 W station.

When is the first frost in Arlington, SD?

The median first fall frost near 57212 is October 2, giving a median frost-free growing season of 151 days.

When should I plant tomatoes in 57212?

Start tomato seeds indoors around Mar 8 – Mar 22 and set transplants outside around May 10 – May 24, one to three weeks after the median last frost.

How much rain and snow does 57212 get?

About 26.2 inches of precipitation a year (NOAA 1991–2020 normals, Arlington 1 W station).

How hot do summers get in Arlington, SD?

The average high peaks at 83 °F in July, with about 10 days a year at 90 °F or more.

What kind of soil does 57212 have?

The USDA soil survey maps Poinsett at the center of ZIP 57212: silty clay loam, well drained, pH about 6.7 (neutral).

Did spring come early in Arlington, SD in 2026?

Spring leaf-out near 57212 came on Apr 3 in 2026, 14 days earlier than the 1991–2020 average (Apr 17), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Arlington, SD?

Long-day onions: the longest day near 57212 is 15 h 32 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).