USDA zone 5a in South Dakota

−20 to −15 °F avg. annual extreme minimum · 57 locations in this group · NOAA 1991–2020 normals

USDA plant hardiness zone 5a covers 57 locations across South Dakota (average annual extreme minimum −20 to −15 °F): Allen, SD, Armour, SD, Ashland Heights, SD, Beresford, SD, Blucksberg Mountain, SD, Bonesteel, SD, and 51 more. Average last spring frost across this group ranges April 27 (Yankton) to May 28 (Johnson Siding), and growing seasons run 112–165 days (Johnson Siding to Marty) — even within one state, because hardiness sets winter survival, not planting dates. The table below gives every South Dakota location's own frost dates; the printable planting calendar uses Sturgis, this group's median-season location.

USDA zone
5a−20 to −15 °F
Last frost range
Apr 27–May 28avg, 32°F
First frost range
Sep 18–Oct 13avg, 32°F
Growing season range
112–165days

Locations in this group

Every location below shares this zone and a nearby weather station, but keeps its own frost dates — find your town for its own numbers, or use the ZIP planner on the home page for an instant personalized answer.

Own frost dates per location.
LocationAlso coversNearest stationLast frostFirst frostSeason (days)
AllenMartinMartinMay 13Oct 2141
ArmourArmourMay 3Oct 6157
Ashland HeightsHermosa, CaputaRapid City Rgnl ApMay 12Oct 1139
BeresfordCenterville, Hurley, Viborg, Davis, WakondaCenterville 6 SeMay 2Oct 1151
Blucksberg MountainHereford 12 SwMay 8Oct 3147
BonesteelBonesteelMay 3Oct 10159
CanovaHowardMay 5Oct 2149
ChamberlainOacoma, Reliance, PukwanaChamberlain 5 SMay 3Oct 7156
ColomeNew WittenWinnerMay 1Oct 9159
CusterCuster Co ApMay 23Sep 24122
Elk PointPonca, Newcastle, Burbank, Meckling, Wynot, Maskell, +1 moreVermillion 2 SeMay 3Oct 3153
FairburnWind CaveMay 15Sep 29133
FedoraWoonsocket, LetcherForestburg 4 NneMay 9Sep 28140
FreemanMenno, Lesterville, OlivetMennoMay 1Oct 4156
GarretsonSioux Falls 14 NneMay 1Oct 4155
GregoryBurke, Herrick, DallasGregoryMay 6Oct 3149
HamillIdeal, New WittenWinner Wiley FldMay 1Oct 10162
HarrisburgCanton, Lennox, Inwood, Larchwood, Worthing, FairviewCantonMay 2Oct 2151
Hot SpringsHot SpringsMay 16Sep 27133
InteriorInterior 3 NeMay 5Oct 7152
Johnson SidingPiedmontPactola DamMay 28Sep 18112
KadokaWanblee, NorrisLongvalleyMay 9Oct 1143
KennebecPreshoKennebecMay 12Sep 28137
KeystoneMt Rushmore NmemMay 15Oct 1138
KimballCorsica, Plankinton, White Lake, Stickney, New HollandWhite LakeMay 3Oct 5153
KyleKyle 2 EMay 11Oct 1139
LeadLeadMay 18Sep 29133
Manderson-White Horse CreekManderson 3 NeMay 9Oct 4147
Manderson-White Horse CreekPorcupine 11 NMay 17Sep 25130
MartyLake Andes, Geddes, Fairfax, GrossPickstownApr 30Oct 13165
MitchellMount VernonMitchell Muni ApApr 30Oct 5159
MontroseMontrose 8nMay 3Oct 4153
New UnderwoodElm Springs 3 EseMay 8Oct 3146
NorrisBelvidere, White RiverCedar ButteMay 6Oct 4151
North SpearfishSpearfishMay 12Oct 2143
OglalaOglala 1sMay 7Oct 4149
OkatonDraper, MurdoMurdoMay 3Oct 9158
OkreekWoodWoodMay 10Oct 1143
ParkstonFulton, Alexandria, Spencer, Ethan, DimockAlexandriaMay 8Sep 29143
PhilipPhilip ApMay 11Sep 30141
Pine RidgeWounded Knee, White ClayPine Ridge ApMay 16Sep 27132
PlatteAcademy 2neApr 30Oct 8159
QuinnCottonwood 2 EMay 16Sep 26132
SalemParker, Bridgewater, Marion, Canistota, Emery, MonroeBridgewaterApr 30Oct 7161
Sioux FallsBrandon, Tea, Hartford, Crooks, Renner Corner, Valley Springs, +3 moreSioux FallsMay 1Oct 6157
SmithwickOelrichsOelrichsMay 15Sep 30137
SmithwickOralOralMay 15Sep 27133
Spring CreekParmelee, CodyHarringtonMay 11Oct 1143
Sturgis *WhitewoodFt MeadeMay 8Oct 3147
SummersetWonderland HomesRapid City 4nwMay 10Oct 5147
Two StrikeMissionMissionMay 9Oct 1146
TyndallSpringfield, Scotland, Kaylor, Avon, Tripp, TaborTyndallMay 1Oct 7158
VivianPresho 7 NwMay 12Sep 29140
WagnerDelmont, DanteWagnerApr 29Oct 9164
WallWastaWastaMay 10Oct 1141
Wessington SpringsLaneWessington SpringsMay 2Oct 8157
YanktonSt. Helena, Mission Hill, Irene, Gayville, Volin, Jamesville ColonyYankton 2 EApr 27Oct 11164

* Sturgis is this group's median-season location — the calendar below is computed from its data.

Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.

Planting calendar (Sturgis, representative)

Computed from Sturgis's average frost dates — the median-season location in this South Dakotazone 5a group. hatched = start seeds indoors, solid green = plant out, teal = a fall sowing, and the terracotta dot marks the estimated first harvest. Ranges are extension-guide planning guidance, not guarantees — your own location's dates may run a week or two earlier or later (see the table above).

  • Start indoors
  • Plant out
  • Fall sowing
  • First harvest
Planting windows for Sturgis (South Dakota, zone 5a), this group's representative location.
CropFrost toleranceStart indoorsPlant outFirst harvestFall plantingSeason fit
TomatoTenderMar 13 – Mar 27May 15 – May 22Jul 14 – Aug 3matures comfortably
PepperVery tenderFeb 27 – Mar 13May 22 – May 29Jul 21 – Aug 20matures comfortably
CucumberTenderApr 10 – Apr 17May 15 – May 22Jul 4 – Jul 24matures comfortably
Summer squash / zucchiniTenderMay 15 – May 22Jun 29 – Jul 14matures comfortably
Bush beanTenderMay 15 – May 22Jul 4 – Jul 14Aug 4 – Aug 14matures comfortably
Sweet cornTenderMay 8 – May 22Jul 7 – Aug 6matures comfortably
BasilVery tenderMar 27 – Apr 10May 15 – May 22Jun 14 – Jun 29matures comfortably
LettuceHalf-hardyMar 27 – Apr 10Apr 10 – Apr 24May 25 – Jun 9Jul 21 – Aug 5matures comfortably
PeaHardyMar 27 – Apr 10May 21 – Jun 5Jul 11 – Jul 26matures comfortably
SpinachHardyMar 27 – Apr 10May 6 – May 16Jul 31 – Aug 10matures comfortably
CarrotHalf-hardyApr 17 – Apr 24Jun 16 – Jul 6Jul 1 – Jul 21matures comfortably
BroccoliHalf-hardyMar 13 – Mar 27Apr 10 – Apr 24Jun 4 – Jun 24Jul 6 – Jul 26matures comfortably

Which crops fit this growing season

Using Sturgis's own 147-day growing season (32°F, NOAA 1991–2020 median) against each crop's real days-to-maturity range: 12 of 12 crops mature here with comfortable margin. A different location in the table above with a longer or shorter season will get a different mix — the ZIP planner on the home page gives your own.

Frost & freeze dates (Sturgis)

From NOAA's 1991–2020 Climate Normals at station USC00393069. The median (p50) is the average date; the 90%-safe column is the date the freeze has passed in about 9 years out of 10 — the conservative date to plant after or harvest before.

Freeze probabilities by temperature threshold (MM/DD, NOAA 1991–2020), Sturgis.
ThresholdLast spring — avgLast spring — 90%-safeFirst fall — avgFirst fall — 90%-safeSeason (days)
36°FMay 19May 31Sep 24Oct 6127
32°F (freeze)May 8May 21Oct 3Oct 17147
28°FApr 28May 11Oct 13Oct 27167
24°FApr 17May 1Oct 23Nov 5187

Growing degree days

Growing degree days (GDD) accumulate warmth above a base temperature over the year — a better predictor of crop development than the calendar alone. This group's median GDD (base 50°F) across all 57 locations is 2,787; Sturgis's own reading is shown below.

Annual growing degree days for Sturgis (°F·days, NOAA 1991–2020).
Model°F·daysUsed for
Base 50°F (warm-season)2,685standard warm-season base (tomato, corn, beans)
Base 40°F (cool-season)4,744cool-season crops (brassicas, greens)

Hardiness zone 5a in South Dakota

Zone 5a means an average annual extreme minimum winter temperature of about −20 to −15 °F on the USDA's 2023 map — the number that tells you which perennials, shrubs, and trees reliably survive an average winter here. It does not set your planting dates, which come from the frost calendar above. South Dakota spans 4 hardiness zones in this dataset — see all South Dakota locations for the full range, including zones4a, 4b, 5b.

Explore zone 5a in other states at zone 5a, or see all USDA hardiness zones.

Frequently asked questions

What does USDA hardiness zone 5a mean in South Dakota?
Zone 5a means an average annual extreme minimum winter temperature of −20 to −15 °F — the standard USDA measure of which perennials survive winter. 57 locations in South Dakota fall in this zone. It does not set planting dates; see the frost calendar below for that.
Where in South Dakota's zone 5a is the growing season longest?
Marty runs the longest season on this page at about 165 days; Johnson Siding is shortest at about 112 days — they share the same hardiness zone, but they sit at different weather stations, so their frost calendars differ.
When should I plant tomatoes in South Dakota's zone 5a?
Using Sturgis's frost dates (this page's median-season location): start seeds indoors about Mar 13 – Mar 27, then transplant outside about May 15 – May 22. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.
Does every location in South Dakota's zone 5a have the same frost dates?
No — they do not all share a weather station, so frost dates vary by a week or more across the 57 locations listed (see the table above for each location's own dates).

Sources & method

Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020, one reading per location's own nearest station (see the table above). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to each location's ZIP. Planting windows are computed by counting from the average last and first frost using per-crop offsets synthesized from U.S. Cooperative Extension guides — the full method and citations are on the methodology page.