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

Planting zone for 57544 — Kennebec, SD

ZIP code 57544 (Kennebec, Lyman County) is in USDA zone 5a: the coldest winter night averages −20 to −15 °F. The median last spring frost is May 12 and the first fall frost September 28.

Where ZIP 57544 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.

Zone5a−20 to −15 °F
Coldest night−28.9 to −26.1 °C
Last frostMay 12
First frostSep 28
2012 zone4b

Was 4b 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 5a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Kennebec, 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 Kennebec, SD

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMay 12median — 50% chance of a later frost
Safe for tender plantsMay 26only 10% chance of frost after
First fall frostSeptember 28median — 10% chance by Sep 15
Growing season137 daysfrost-free, median

A hard freeze (28 °F) usually ends around May 3 and returns around October 5.

From the NOAA station Kennebec, SD — within 1 mile, elevation 1,680 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 57544

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 31 – Apr 14
SpinachSow outdoors · Mar 31 – Apr 21
Broccoli, cabbageStart indoors · Mar 3 – Mar 17
Broccoli, cabbageTransplant · Apr 21 – May 5
Onion setsPlant outdoors · Apr 14 – Apr 28
PotatoesPlant outdoors · Apr 21 – May 5
LettuceSow outdoors · Apr 14 – Apr 28
Carrots, beetsSow outdoors · Apr 21 – May 5
TomatoesStart indoors · Mar 17 – Mar 31
TomatoesTransplant · May 19 – Jun 2
Peppers, eggplantStart indoors · Mar 3 – Mar 17
Peppers, eggplantTransplant · May 26 – Jun 9
BeansSow outdoors · May 19 – Jun 2
Sweet cornSow outdoors · May 19 – Jun 2
Cucumbers, squashSow outdoors · May 19 – Jun 2
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 12) 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 57544 came on Mar 22 — 16 days earlier than the 1991–2020 average (Apr 7).

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 5a in South Dakota

452 plants native to the lower 48 states, recorded in South Dakota, and rated by the USDA to survive −20 °F or colder — the bottom of zone 5a. Each links to its USDA PLANTS profile.

Trees 23

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °Fbalsam poplar80 ft · blooms late spring · high shade tolerance · to −79 °Fblack locust60 ft · blooms spring · high shade tolerance · to −37 °Fblack maple100 ft · blooms late spring · low shade tolerance · to −47 °Fblack walnut100 ft · blooms late spring · high shade tolerance · to −28 °F

Shrubs 70

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °Falderleaf mountain mahogany15 ft · blooms late spring · medium shade tolerance · to −41 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican plum24 ft · blooms mid spring · high shade tolerance · to −38 °Fbeaked hazelnut15 ft · blooms early spring · low shade tolerance · to −47 °F

Wildflowers & perennials 202

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °Falpine bistort1 ft · blooms mid spring · high shade tolerance · to −38 °Falpine mountainsorrel1 ft · blooms mid summer · medium shade tolerance · to −43 °Falpine sweetvetch2 ft · blooms early summer · high shade tolerance · to −62 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °F

Grasses 144

Alaska oniongrass3 ft · blooms mid spring · low shade tolerance · to −33 °Falkali cordgrass3 ft · blooms late summer · high shade tolerance · to −38 °Falkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °Falpine timothy1.4 ft · blooms late spring · medium shade tolerance · to −43 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °F

Vines 5

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °FVirginia creeper1 ft · blooms late spring · medium shade tolerance · to −28 °Fwestern white clematis1 ft · blooms mid summer · medium shade tolerance · to −38 °F

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 Kennebec, SD.

Soil in Kennebec, SD

The soil mapped at the center of ZIP 57544 is Millboro — silty clay, well drained.

TextureSilty clayholds water and nutrients; slow to drain and warm up
pH7.0neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter3%moderate
Hydrologic groupDwater soaks in very slowly
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Millboro silty clay, 3 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 57544; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Kennebec, SD

Summer high90 °Faverage high, July
Winter low9 °Faverage low, January
Hot days44days a year at 90 °F or more
Freezing nights166nights a year at 32 °F or less
Growing degree days3,084base 50 °F — the season’s usable heat
Longest day15 h 28 mindaylight on June 21
Shortest day8 h 54 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation20.8 inper year, rain and melted snow
Snowfall40 inper year; 47 days with snow on the ground

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 32 °F, low 9 °F 32°9° JanFebruary: average high 36 °F, low 13 °F 36°13° FebMarch: average high 49 °F, low 23 °F 49°23° MarApril: average high 62 °F, low 33 °F 62°33° AprMay: average high 72 °F, low 45 °F 72°45° MayJune: average high 82 °F, low 56 °F 82°56° JunJuly: average high 90 °F, low 61 °F 90°61° JulAugust: average high 88 °F, low 59 °F 88°59° AugSeptember: average high 80 °F, low 50 °F 80°50° SepOctober: average high 64 °F, low 36 °F 64°36° OctNovember: average high 47 °F, low 22 °F 47°22° NovDecember: average high 34 °F, low 13 °F 34°13° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″January: 0.45 in precipitation, 5.5 in snowfall 0.5❄6 JanFebruary: 0.59 in precipitation, 7.6 in snowfall 0.6❄8 FebMarch: 0.96 in precipitation, 5.5 in snowfall 1.0❄6 MarApril: 2.34 in precipitation, 6.2 in snowfall 2.3❄6 AprMay: 3.29 in precipitation 3.3 MayJune: 3.48 in precipitation 3.5 JunJuly: 2.84 in precipitation 2.8 JulAugust: 2.31 in precipitation 2.3 AugSeptember: 1.72 in precipitation 1.7 SepOctober: 1.63 in precipitation, 1.6 in snowfall 1.6❄2 OctNovember: 0.71 in precipitation, 6 in snowfall 0.7❄6 NovDecember: 0.47 in precipitation, 7.2 in snowfall 0.5❄7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Kennebec, SD (within 1 mile); precipitation: Kennebec, SD (within 1 mile). 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.

575685a
Presho, SD · 13 mi
575695a
Reliance, SD · 15 mi
575415a
Ideal, SD · 20 mi
573655a
Oacoma, SD · 22 mi
575765a
Vivian, SD · 22 mi
575484b
Lower Brule, SD · 23 mi
575345a
Hamill, SD · 24 mi
573394b
Fort Thompson, SD · 25 mi

South Dakota planting zones →

Questions about 57544

What planting zone is ZIP code 57544?

ZIP code 57544 (Kennebec, SD) is in USDA hardiness zone 5a on the 2023 map: the coldest night of an average winter reaches −20 to −15 °F (−28.9 to −26.1 °C).

When is the last frost in Kennebec, SD?

The median last spring frost (32 °F) near 57544 is May 12; after May 26 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Kennebec station.

When is the first frost in Kennebec, SD?

The median first fall frost near 57544 is September 28, giving a median frost-free growing season of 137 days.

When should I plant tomatoes in 57544?

Start tomato seeds indoors around Mar 17 – Mar 31 and set transplants outside around May 19 – Jun 2, one to three weeks after the median last frost.

How much rain and snow does 57544 get?

About 20.8 inches of precipitation a year and 40 inches of snowfall (NOAA 1991–2020 normals, Kennebec station).

How hot do summers get in Kennebec, SD?

The average high peaks at 90 °F in July, with about 44 days a year at 90 °F or more.

What kind of soil does 57544 have?

The USDA soil survey maps Millboro at the center of ZIP 57544: silty clay, well drained, pH about 7.0 (neutral).

Did spring come early in Kennebec, SD in 2026?

Spring leaf-out near 57544 came on Mar 22 in 2026, 16 days earlier than the 1991–2020 average (Apr 7), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Kennebec, SD?

Long-day onions: the longest day near 57544 is 15 h 28 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 57544 change?

Yes. The 2012 USDA map put 57544 in zone 4b; the 2023 map puts it in zone 5a. The newer map uses 1991–2020 data and more weather stations.