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

Planting zone for 57471 — Roscoe, SD

ZIP code 57471 (Roscoe, Edmunds County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is May 7 and the first fall frost October 3.

Where ZIP 57471 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 7

First frostOct 3

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 Roscoe, 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 Roscoe, SD

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 7median — 50% chance of a later frost

Safe for tender plantsMay 20only 10% chance of frost after

First fall frostOctober 3median — 10% chance by Sep 19

Growing season148 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 29 and returns around October 12.

From the NOAA station Roscoe, SD — 4 miles away, elevation 1,834 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 57471

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 26 – Apr 9

SpinachSow outdoors · Mar 26 – Apr 16

Broccoli, cabbageStart indoors · Feb 26 – Mar 12

Broccoli, cabbageTransplant · Apr 16 – Apr 30

Onion setsPlant outdoors · Apr 9 – Apr 23

PotatoesPlant outdoors · Apr 16 – Apr 30

LettuceSow outdoors · Apr 9 – Apr 23

Carrots, beetsSow outdoors · Apr 16 – Apr 30

TomatoesStart indoors · Mar 12 – Mar 26

TomatoesTransplant · May 14 – May 28

Peppers, eggplantStart indoors · Feb 26 – Mar 12

Peppers, eggplantTransplant · May 21 – Jun 4

BeansSow outdoors · May 14 – May 28

Sweet cornSow outdoors · May 14 – May 28

Cucumbers, squashSow outdoors · May 14 – May 28

Fall lettuce, spinachSow outdoors · Aug 8 – Aug 22

GarlicPlant cloves · Sep 19 – Oct 24

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 7) and first fall frost (Oct 3) 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 57471 came on Apr 12 — 7 days earlier than the 1991–2020 average (Apr 19).

average
Apr 192026
Apr 12

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 4b in South Dakota

430 plants native to the lower 48 states, recorded in South Dakota, and rated by the USDA to survive −25 °F or colder — the bottom of zone 4b. 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 Roscoe, SD.

Soil in Roscoe, SD

The soil mapped at the center of ZIP 57471 is Williams — loam, well drained.

TextureLoama good balance for most vegetables

pH7.2neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter4%moderate

Hydrologic groupBwater soaks in moderately

Farmland classFarmland of statewide importanceUSDA classification

Map unit: Williams-Bowbells loams, 6 to 9 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 57471; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Roscoe, SD

Summer high83 °Faverage high, July

Winter low3 °Faverage low, January

Hot days14days a year at 90 °F or more

Freezing nights182nights a year at 32 °F or less

Growing degree days2,318base 50 °F — the season’s usable heat

Longest day15 h 40 mindaylight on June 21

Shortest day8 h 43 mindaylight on December 21

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

Precipitation21.4 inper year, rain and melted snow

Snowfall47 inper year; 99 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: Roscoe, SD (4 mi away); precipitation: Roscoe, SD (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 4b.

South Dakota planting zones →

Questions about 57471

What planting zone is ZIP code 57471?

ZIP code 57471 (Roscoe, 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 Roscoe, SD?

The median last spring frost (32 °F) near 57471 is May 7; after May 20 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Roscoe station.

When is the first frost in Roscoe, SD?

The median first fall frost near 57471 is October 3, giving a median frost-free growing season of 148 days.

When should I plant tomatoes in 57471?

Start tomato seeds indoors around Mar 12 – Mar 26 and set transplants outside around May 14 – May 28, one to three weeks after the median last frost.

How much rain and snow does 57471 get?

About 21.4 inches of precipitation a year and 47 inches of snowfall (NOAA 1991–2020 normals, Roscoe station).

How hot do summers get in Roscoe, SD?

The average high peaks at 83 °F in July, with about 14 days a year at 90 °F or more.

What kind of soil does 57471 have?

The USDA soil survey maps Williams at the center of ZIP 57471: loam, well drained, pH about 7.2 (neutral).

Did spring come early in Roscoe, SD in 2026?

Spring leaf-out near 57471 came on Apr 12 in 2026, 7 days earlier than the 1991–2020 average (Apr 19), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Roscoe, SD?

Long-day onions: the longest day near 57471 is 15 h 40 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).