USDA hardiness zone 6a

In zone 6a the average coldest winter night reaches -10°F to -5°F. Plants labeled for zone 6 (or a colder zone) can survive the winter outdoors here. 443 U.S. cities with 10,000+ residents are in this zone — the largest are listed below.

CityStateZoneAvg. last frostAvg. first frost
DenverCO6aApr 30Oct 12
MilwaukeeWI6aApr 26Oct 22
OmahaNE6aApr 18Oct 21
Colorado SpringsCO6aMay 3Oct 8
AuroraCO6aMay 4Oct 8
LincolnNE6aApr 24Oct 13
Fort WayneIN6aApr 24Oct 21
WorcesterMA6aApr 23Oct 21
Grand RapidsMI6aMay 6Oct 10
LakewoodCO6aMay 3Oct 7
JolietIL6aApr 19Oct 25
SyracuseNY6aApr 29Oct 19
ThorntonCO6aMay 2Oct 11
Ann ArborMI6aMay 5Oct 10
WestminsterCO6aMay 2Oct 11
ArvadaCO6aMay 5Oct 5
PeoriaIL6aApr 16Oct 23
SpringfieldIL6aApr 15Oct 22
North PeoriaIL6aApr 16Oct 23
LansingMI6aMay 1Oct 13
ManchesterNH6aApr 30Oct 11
CentennialCO6aMay 5Oct 8
PuebloCO6aApr 30Oct 9
BoulderCO6aMay 6Oct 5
South BendIN6aApr 23Oct 23
AlbanyNY6aApr 27Oct 15
KenoshaWI6aApr 19Oct 26
FlintMI6aMay 6Oct 10
Highlands RanchCO6aMay 5Oct 8
West AlbanyNY6aApr 27Oct 15
CarmelIN6aApr 21Oct 21
WaukeganIL6aApr 30Oct 19
NashuaNH6aApr 30Oct 12
ChampaignIL6aApr 15Oct 24
CiceroIL6aApr 11Oct 31
BloomingtonIL6aApr 21Oct 20
RacineWI6aApr 20Oct 24
HammondIN6aApr 23Oct 20
GaryIN6aApr 22Oct 27
FishersIN6aApr 21Oct 21
Saint JosephMO6aApr 19Oct 17
KalamazooMI6aApr 28Oct 18
Arlington HeightsIL6aApr 19Oct 26
WaterfordMI6aApr 29Oct 20
EvanstonIL6aApr 26Oct 21
WyomingMI6aMay 6Oct 10
BolingbrookIL6aApr 20Oct 22
Rochester HillsMI6aApr 26Oct 22
DecaturIL6aApr 14Oct 24
LafayetteIN6aApr 26Oct 18
FlagstaffAZ6aJun 4Sep 28
MuncieIN6aApr 16Oct 25
PortlandME6aApr 26Oct 15
SchenectadyNY6aApr 27Oct 15
BroomfieldCO6aMay 2Oct 11
SkokieIL6aApr 26Oct 21
West Bloomfield TownshipMI6aApr 29Oct 20
YoungstownOH6aMay 1Oct 17
HaverhillMA6aMay 1Oct 12
Council BluffsIA6aApr 18Oct 21
Terre HauteIN6aApr 15Oct 19
PontiacMI6aApr 26Oct 22
SpringfieldOH6aApr 25Oct 19
NoblesvilleIN6aApr 21Oct 21
NoviMI6aMay 1Oct 17
Des PlainesIL6aApr 16Oct 28
Orland ParkIL6aApr 19Oct 22
KokomoIN6aApr 27Oct 18
Tinley ParkIL6aApr 23Oct 20
Oak LawnIL6aApr 10Nov 1
ChicopeeMA6aMay 3Oct 8
BerwynIL6aApr 11Oct 31
ManhattanKS6aApr 16Oct 19
GreenwoodIN6aApr 20Oct 21
AndersonIN6aApr 19Oct 23
North ChicopeeMA6aMay 3Oct 8
Mount ProspectIL6aApr 19Oct 26
PocatelloID6aMay 2Oct 11
NormalIL6aApr 25Oct 16
Commerce CityCO6aMay 4Oct 8
ElkhartIN6aApr 26Oct 21
Oak ParkIL6aApr 11Oct 31
Battle CreekMI6aApr 30Oct 19
KentwoodMI6aMay 6Oct 10
LoganUT6aMay 8Oct 2
TroyNY6aApr 19Oct 26
Downers GroveIL6aApr 28Oct 16
SaginawMI6aApr 29Oct 21
SheboyganWI6aApr 25Oct 23
East LansingMI6aApr 28Oct 17
MishawakaIN6aApr 23Oct 23
PortageMI6aApr 28Oct 18
NewarkOH6aApr 29Oct 16
LawrenceIN6aApr 18Oct 26
GlenviewIL6aApr 26Oct 21
MansfieldOH6aApr 26Oct 22
LittletonCO6aMay 2Oct 11
BinghamtonNY6aMay 2Oct 11
ElmhurstIL6aApr 16Oct 28
West LafayetteIN6aApr 26Oct 18
LombardIL6aApr 28Oct 16
UrbanaIL6aApr 15Oct 24
MidlandMI6aApr 29Oct 16
WestfieldMA6aMay 3Oct 8
LeominsterMA6aApr 29Oct 11
Buffalo GroveIL6aApr 19Oct 26
QuincyIL6aApr 8Oct 30
HolyokeMA6aMay 3Oct 8
FitchburgMA6aMay 1Oct 9
WarrenOH6aMay 8Oct 12
AmherstMA6aMay 5Oct 8
LancasterOH6aApr 22Oct 24
RomeovilleIL6aApr 20Oct 22
NorthglennCO6aMay 2Oct 11
WheelingIL6aApr 19Oct 26
LimaOH6aApr 24Oct 24
Park RidgeIL6aApr 16Oct 28
AddisonIL6aApr 16Oct 28
Calumet CityIL6aApr 23Oct 20
PortageIN6aApr 22Oct 27
WestfieldIN6aApr 21Oct 21
Clifton ParkNY6aApr 27Oct 15
MarionOH6aApr 25Oct 20
West TorringtonCT6aMay 8Oct 5
RichmondIN6aApr 24Oct 20
BoardmanOH6aMay 8Oct 12
Oak CreekWI6aApr 22Oct 26
MerrillvilleIN6aApr 22Oct 25
TorringtonCT6aMay 8Oct 5
Derry VillageNH6aApr 30Oct 11
Bay CityMI6aApr 27Oct 20
ShrewsburyMA6aApr 23Oct 21
Dakota RidgeCO6aMay 2Oct 11
NorthbrookIL6aApr 26Oct 21
WoodridgeIL6aApr 28Oct 16
Elk Grove VillageIL6aApr 16Oct 28
PekinIL6aApr 16Oct 23
JacksonMI6aMay 1Oct 14
EnglewoodCO6aMay 2Oct 11
GoshenIN6aApr 26Oct 21
Security-WidefieldCO6aMay 3Oct 8
ValparaisoIN6aApr 22Oct 25
Ken CarylCO6aMay 2Oct 11
DanvilleIL6aApr 21Oct 20
Michigan CityIN6aApr 19Oct 27
Wheat RidgeCO6aMay 5Oct 5
GurneeIL6aApr 30Oct 19
DoverNH6aMay 3Oct 10
IthacaNY6aMay 11Oct 3
PlainfieldIN6aApr 12Oct 27
GrangerIN6aApr 23Oct 23
LibertyMO6aApr 19Oct 17
Chicago HeightsIL6aApr 23Oct 20
JamestownNY6aMay 8Oct 13
RochesterNH6aApr 30Oct 9
NilesIL6aApr 16Oct 28
Highland ParkIL6aApr 26Oct 21
AustintownOH6aMay 8Oct 12
Pueblo WestCO6aApr 26Oct 13
SalemNH6aApr 21Oct 21
North ChicagoIL6aApr 30Oct 19
GlenvilleNY6aMay 7Oct 7
BurbankIL6aApr 10Nov 1
MarionIN6aApr 26Oct 20
DracutMA6aApr 30Oct 10
ScherervilleIN6aApr 23Oct 20
BurtonMI6aMay 8Oct 5
East ChicagoIN6aApr 23Oct 20
NorthamptonMA6aMay 5Oct 8
HobartIN6aApr 22Oct 27
LansingIL6aApr 23Oct 20
ElmiraNY6aMay 6Oct 11
Glen EllynIL6aApr 28Oct 16
Oak ForestIL6aApr 23Oct 20
VestalNY6aMay 5Oct 12
FountainCO6aMay 3Oct 8
LafayetteCO6aMay 2Oct 11
West ScarboroughME6aApr 26Oct 15
WilmetteIL6aApr 26Oct 21
AuburnNY6aMay 2Oct 18
Back MountainPA6aApr 23Oct 20
WoosterOH6aApr 30Oct 12
MerrimackNH6aApr 30Oct 12
MedinaOH6aApr 29Oct 19
Vernon HillsIL6aApr 29Oct 20
ZionsvilleIN6aApr 21Oct 20
Mount PleasantWI6aApr 20Oct 24
Mount PleasantMI6aApr 30Oct 20
Forest HillsMI6aApr 29Oct 20
New LenoxIL6aApr 19Oct 25
TroyOH6aApr 18Oct 23
South PortlandME6aApr 26Oct 15
BurlingtonIA6aApr 15Oct 20
Melrose ParkIL6aApr 16Oct 28
HarveyIL6aApr 23Oct 20
LockportIL6aApr 20Oct 22
BrownsburgIN6aApr 12Oct 29
Saginaw Township NorthMI6aApr 29Oct 21
WestmontIL6aApr 28Oct 16
HastingsNE6aApr 22Oct 16
Elmwood ParkIL6aApr 16Oct 28
WalkerMI6aMay 6Oct 10
Homer GlenIL6aApr 20Oct 22
ColumbineCO6aMay 2Oct 11
Rolling MeadowsIL6aApr 19Oct 26
ZionIL6aApr 30Oct 21
MaywoodIL6aApr 11Oct 31
HoltMI6aApr 28Oct 17
WaverlyMI6aMay 1Oct 13
South Portland GardensME6aApr 26Oct 15
Blue IslandIL6aApr 10Nov 1
Morton GroveIL6aApr 26Oct 21
GallupNM6aMay 11Oct 7
DoltonIL6aApr 23Oct 20
East PeoriaIL6aApr 16Oct 23
SolonOH6aApr 8Nov 12
MunsterIN6aApr 23Oct 20
HighlandIN6aApr 23Oct 20
Auburn HillsMI6aApr 26Oct 22
DarienIL6aApr 19Oct 22
LudlowMA6aMay 3Oct 14
OxfordOH6aApr 19Oct 22
AllianceOH6aMay 2Oct 13
South HollandIL6aApr 23Oct 20
DerryNH6aApr 30Oct 11
Villa ParkIL6aApr 28Oct 16
Park ForestIL6aApr 23Oct 20
La PorteIN6aApr 19Oct 27
WadsworthOH6aApr 29Oct 19
WestfordMA6aApr 30Oct 10
PortsmouthNH6aMay 4Oct 8
GreenfieldIN6aApr 19Oct 22
OkemosMI6aApr 28Oct 17
Fairfield HeightsIN6aApr 12Oct 29
South MilwaukeeWI6aApr 22Oct 26
CharlestonIL6aApr 15Oct 23
BedfordNH6aApr 21Oct 19
Crest HillIL6aApr 20Oct 22
SidneyOH6aApr 27Oct 20
PiquaOH6aApr 18Oct 23
LathamNY6aApr 27Oct 15
AdrianMI6aMay 1Oct 15
RotterdamNY6aApr 27Oct 15
LibertyvilleIL6aApr 30Oct 19
LouisvilleCO6aMay 6Oct 5
GoldenCO6aMay 3Oct 14
AshlandOH6aApr 30Oct 15
YpsilantiMI6aMay 5Oct 10
MokenaIL6aApr 23Oct 20
Evergreen ParkIL6aApr 10Nov 1
GreenfieldMA6aMay 1Oct 11
PapillionNE6aApr 17Oct 19
Lake ForestIL6aApr 30Oct 19
HomewoodIL6aApr 23Oct 20
AlsipIL6aApr 10Nov 1
BellwoodIL6aApr 16Oct 28
Broadview HeightsOH6aApr 20Nov 3
HaslettMI6aApr 28Oct 17
MattesonIL6aApr 23Oct 20
ShelbyvilleIN6aApr 17Oct 22
JacksonvilleIL6aApr 17Oct 21
Amherst CenterMA6aMay 5Oct 8
DeerfieldIL6aApr 26Oct 21
BrookfieldIL6aApr 11Oct 31
TwinsburgOH6aApr 30Oct 21
Mayfield HeightsOH6aApr 26Oct 31
Brigham CityUT6aMay 5Oct 5
FrankfortIL6aApr 23Oct 20
NilesOH6aMay 8Oct 12
Goodings GroveIL6aApr 19Oct 22
MacombIL6aApr 17Oct 22
BensenvilleIL6aApr 16Oct 28
CudahyWI6aApr 19Oct 29
AmesburyMA6aMay 1Oct 12
Franklin ParkIL6aApr 16Oct 28
SherrelwoodCO6aMay 2Oct 11
PalmerMA6aMay 3Oct 14
MattoonIL6aApr 11Oct 29
HannibalMO6aApr 10Oct 27
LogansportIN6aApr 20Oct 23
OswegoNY6aApr 22Oct 29
TiffinOH6aApr 23Oct 23
South HadleyMA6aMay 5Oct 8
HinsdaleIL6aApr 28Oct 16
New CastleIN6aApr 27Oct 17
AllendaleMI6aApr 30Oct 24
Palos HillsIL6aApr 19Oct 22
KirksvilleMO6aApr 21Oct 19
HuntingtonIN6aMay 1Oct 14
La VistaNE6aApr 17Oct 19
NorwalkOH6aApr 25Oct 25
Country Club HillsIL6aApr 23Oct 20
LemontIL6aApr 20Oct 22
DefianceOH6aApr 22Oct 24
Mount VernonOH6aMay 1Oct 10
WestchesterIL6aApr 11Oct 31
AuburnMA6aApr 23Oct 21
WashingtonIL6aApr 21Oct 17
EasthamptonMA6aMay 3Oct 8
JenisonMI6aMay 6Oct 10