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

Planting zone for 57755 — Ludlow, SD

ZIP code 57755 (Ludlow, Harding County) is in USDA zone 4b: the coldest winter night averages −25 to −20 °F. The median last spring frost is May 16 and the first fall frost September 26.

Where ZIP 57755 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 16

First frostSep 26

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 Ludlow, 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 Ludlow, SD

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMay 16median — 50% chance of a later frost

Safe for tender plantsMay 29only 10% chance of frost after

First fall frostSeptember 26median — 10% chance by Sep 9

Growing season131 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 6 and returns around October 4.

From the NOAA station Ludlow 3 Sse, SD — 6 miles away, elevation 2,989 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 57755

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Apr 4 – Apr 18

SpinachSow outdoors · Apr 4 – Apr 25

Broccoli, cabbageStart indoors · Mar 7 – Mar 21

Broccoli, cabbageTransplant · Apr 25 – May 9

Onion setsPlant outdoors · Apr 18 – May 2

PotatoesPlant outdoors · Apr 25 – May 9

LettuceSow outdoors · Apr 18 – May 2

Carrots, beetsSow outdoors · Apr 25 – May 9

TomatoesStart indoors · Mar 21 – Apr 4

TomatoesTransplant · May 23 – Jun 6

Peppers, eggplantStart indoors · Mar 7 – Mar 21

Peppers, eggplantTransplant · May 30 – Jun 13

BeansSow outdoors · May 23 – Jun 6

Sweet cornSow outdoors · May 23 – Jun 6

Cucumbers, squashSow outdoors · May 23 – Jun 6

Fall lettuce, spinachSow outdoors · Aug 1 – Aug 15

GarlicPlant cloves · Sep 12 – Oct 17

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 16) and first fall frost (Sep 26) 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 57755 came on Mar 24 — 22 days earlier than the 1991–2020 average (Apr 15).

average
Apr 152026
Mar 24

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 Ludlow, SD.

Soil in Ludlow, SD

The soil mapped at the center of ZIP 57755 is Amor — loam, well drained.

TextureLoama good balance for most vegetables

pH7.0neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter4.5%moderate

Hydrologic groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Amor-Cabba 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 57755; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Ludlow, SD

Summer high84 °Faverage high, July

Winter low9 °Faverage low, January

Hot days19days a year at 90 °F or more

Freezing nights179nights a year at 32 °F or less

Growing degree days2,159base 50 °F — the season’s usable heat

Longest day15 h 44 mindaylight on June 21

Shortest day8 h 39 mindaylight on December 21

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

Precipitation17.1 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: Ludlow 3 Sse, SD (6 mi away); precipitation: Ludlow 3 Sse, SD (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 4b.

Prairie City, SD · 36 mi

South Dakota planting zones →

Questions about 57755

What planting zone is ZIP code 57755?

ZIP code 57755 (Ludlow, 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 Ludlow, SD?

The median last spring frost (32 °F) near 57755 is May 16; after May 29 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Ludlow 3 Sse station.

When is the first frost in Ludlow, SD?

The median first fall frost near 57755 is September 26, giving a median frost-free growing season of 131 days.

When should I plant tomatoes in 57755?

Start tomato seeds indoors around Mar 21 – Apr 4 and set transplants outside around May 23 – Jun 6, one to three weeks after the median last frost.

How much rain and snow does 57755 get?

About 17.1 inches of precipitation a year (NOAA 1991–2020 normals, Ludlow 3 Sse station).

How hot do summers get in Ludlow, SD?

The average high peaks at 84 °F in July, with about 19 days a year at 90 °F or more.

What kind of soil does 57755 have?

The USDA soil survey maps Amor at the center of ZIP 57755: loam, well drained, pH about 7.0 (neutral).

Did spring come early in Ludlow, SD in 2026?

Spring leaf-out near 57755 came on Mar 24 in 2026, 22 days earlier than the 1991–2020 average (Apr 15), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Ludlow, SD?

Long-day onions: the longest day near 57755 is 15 h 44 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 57755 change?

Yes. The 2012 USDA map put 57755 in zone 4a; the 2023 map puts it in zone 4b. The newer map uses 1991–2020 data and more weather stations.