Frost dates in South Dakota

Across South Dakota, the typical last spring frost is around May 6 and the first fall frost around Oct 2. Your own dates depend on where you are in the state; find your county below.

Most of the state's last spring frosts fall between May 1 and May 14, and its first fall frosts between Sep 28 and Oct 9.

These are the dates with a 50% chance of a 32°F frost on or after (spring) or on or before (fall), so plan tender crops a week or two after the spring date and keep row cover handy. For dates at your exact ZIP code, use the zone and frost date lookup; for what to plant when, see the planting guide by frost date.

Hardiness zones in South Dakota: zone 4a, zone 4b, zone 5a, zone 5b

Frost dates by county in South Dakota

CountyLast spring frostFirst fall frostGrowing season
AuroraMay 3Oct 5About 155 days
BeadleMay 6Oct 2About 149 days
BennettMay 13Oct 2About 142 days
Bon HommeMay 1Oct 7About 159 days
BrookingsMay 6Oct 1About 148 days
BrownMay 7Sep 29About 145 days
BruleMay 1Oct 7About 159 days
BuffaloMay 6Oct 5About 152 days
ButteMay 8Oct 1About 146 days
CampbellMay 8Oct 1About 146 days
Charles MixApr 30Oct 13About 166 days
ClarkMay 5Oct 5About 153 days
ClayMay 3Oct 3About 153 days
CodingtonMay 7Sep 30About 146 days
CorsonMay 10Sep 30About 143 days
CusterMay 15Sep 29About 137 days
DavisonMay 2Oct 6About 157 days
DayMay 4Oct 6About 155 days
DeuelMay 7Oct 1About 147 days
DeweyMay 10Sep 30About 143 days
DouglasMay 3Oct 6About 156 days
EdmundsMay 7Oct 3About 149 days
Fall RiverMay 15Sep 27About 135 days
FaulkMay 10Sep 29About 142 days
GrantMay 5Oct 2About 150 days
GregoryMay 3Oct 10About 160 days
HaakonMay 11Sep 30About 142 days
HamlinMay 6Oct 1About 148 days
HandMay 10Oct 3About 146 days
HansonApr 30Oct 5About 158 days
HardingMay 17Sep 24About 130 days
HughesMay 17Sep 24About 130 days
HutchinsonMay 1Oct 4About 156 days
HydeMay 12Oct 1About 142 days
JacksonMay 9Oct 1About 145 days
JerauldMay 2Oct 8About 159 days
JonesMay 3Oct 9About 159 days
KingsburyMay 5Oct 4About 152 days
LakeMay 2Oct 5About 156 days
LawrenceMay 12Oct 2About 143 days
LincolnMay 2Oct 2About 153 days
LymanMay 6Oct 7About 154 days
MarshallMay 13Oct 9About 149 days
McCookMay 7Oct 4About 150 days
McPhersonMay 10Sep 30About 143 days
MeadeMay 10Oct 3About 146 days
MelletteMay 6Oct 4About 151 days
MinerMay 5Oct 2About 150 days
MinnehahaMay 1Oct 6About 158 days
MoodyMay 5Oct 1About 149 days
Oglala LakotaMay 11Oct 2About 144 days
PenningtonMay 12Oct 1About 142 days
PerkinsMay 11Sep 30About 142 days
PotterMay 7Oct 2About 148 days
RobertsMay 5Oct 3About 151 days
SanbornMay 9Sep 28About 142 days
SpinkMay 8Oct 1About 146 days
StanleyMay 6Oct 5About 152 days
SullyMay 8Oct 2About 147 days
ToddMay 10Oct 1About 144 days
TrippMay 1Oct 10About 162 days
TurnerMay 2Oct 1About 152 days
UnionMay 1Oct 7About 159 days
WalworthMay 8Oct 1About 146 days
YanktonApr 27Oct 11About 167 days
ZiebachMay 8Oct 2About 147 days

Source: NOAA NCEI U.S. Climate Normals 1991–2020, 50% probability of 32°F, from the weather station nearest each ZIP code; each county shows the middle value across its ZIP codes. Hills, valleys and cities can run a week or more earlier or later.

Frost dates for other states