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

Planting zone for 57256 — Ortley, SD

ZIP code 57256 (Ortley, Roberts County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is May 14 and the first fall frost September 28.

Where ZIP 57256 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 14

First frostSep 28

2012 zone4a

Was 4a 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 4b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Ortley, 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 Ortley, SD

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 14median — 50% chance of a later frost

Safe for tender plantsMay 28only 10% chance of frost after

First fall frostSeptember 28median — 10% chance by Sep 13

Growing season136 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 4 and returns around October 4.

From the NOAA station Summit 1 W, SD — 7 miles away, elevation 1,955 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 57256

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 2 – Apr 16

SpinachSow outdoors · Apr 2 – Apr 23

Broccoli, cabbageStart indoors · Mar 5 – Mar 19

Broccoli, cabbageTransplant · Apr 23 – May 7

Onion setsPlant outdoors · Apr 16 – Apr 30

PotatoesPlant outdoors · Apr 23 – May 7

LettuceSow outdoors · Apr 16 – Apr 30

Carrots, beetsSow outdoors · Apr 23 – May 7

TomatoesStart indoors · Mar 19 – Apr 2

TomatoesTransplant · May 21 – Jun 4

Peppers, eggplantStart indoors · Mar 5 – Mar 19

Peppers, eggplantTransplant · May 28 – Jun 11

BeansSow outdoors · May 21 – Jun 4

Sweet cornSow outdoors · May 21 – Jun 4

Cucumbers, squashSow outdoors · May 21 – Jun 4

Fall lettuce, spinachSow outdoors · Aug 3 – Aug 17

GarlicPlant cloves · Sep 14 – Oct 19

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 14) and first fall frost (Sep 28) 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 57256 came on Apr 18 — 3 days earlier than the 1991–2020 average (Apr 21).

average
Apr 212026
Apr 18

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 Ortley, SD.

Soil in Ortley, SD

The soil mapped at the center of ZIP 57256 is Divide — loam, somewhat poorly drained.

TextureLoama good balance for most vegetables

pH7.7slightly alkaline; most vegetables like 6.0–7.0

DrainageSomewhat poorly drainedconsider raised beds

Organic matter4%moderate

Hydrologic groupB/Dmoderate when drained; wet otherwise

Farmland classPrime farmland if drainedUSDA classification

Map unit: Divide loam, 0 to 2 percent slopes, occasionally flooded.

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 57256; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Ortley, SD

Summer high82 °Faverage high, July

Winter low2 °Faverage low, January

Hot days7days a year at 90 °F or more

Freezing nights180nights a year at 32 °F or less

Growing degree days2,331base 50 °F — the season’s usable heat

Longest day15 h 39 mindaylight on June 21

Shortest day8 h 44 mindaylight on December 21

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

Precipitation25.7 inper year, rain and melted snow

Snowfall59 inper year; 107 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: Summit 1 W, SD (7 mi away); precipitation: Summit 1 W, SD (7 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.

South Shore, SD · 12 mi

Grenville, SD · 19 mi

South Dakota planting zones →

Questions about 57256

What planting zone is ZIP code 57256?

ZIP code 57256 (Ortley, 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 Ortley, SD?

The median last spring frost (32 °F) near 57256 is May 14; after May 28 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Summit 1 W station.

When is the first frost in Ortley, SD?

The median first fall frost near 57256 is September 28, giving a median frost-free growing season of 136 days.

When should I plant tomatoes in 57256?

Start tomato seeds indoors around Mar 19 – Apr 2 and set transplants outside around May 21 – Jun 4, one to three weeks after the median last frost.

How much rain and snow does 57256 get?

About 25.7 inches of precipitation a year and 59 inches of snowfall (NOAA 1991–2020 normals, Summit 1 W station).

How hot do summers get in Ortley, SD?

The average high peaks at 82 °F in July, with about 7 days a year at 90 °F or more.

What kind of soil does 57256 have?

The USDA soil survey maps Divide at the center of ZIP 57256: loam, somewhat poorly drained, pH about 7.7 (slightly alkaline).

Did spring come early in Ortley, SD in 2026?

Spring leaf-out near 57256 came on Apr 18 in 2026, 3 days earlier than the 1991–2020 average (Apr 21), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Ortley, SD?

Long-day onions: the longest day near 57256 is 15 h 39 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 57256 change?

Yes. The 2012 USDA map put 57256 in zone 4a; the 2023 map puts it in zone 4b. The newer map uses 1991–2020 data and more weather stations.