SmogRank / Countries / United States / June 2025
Most polluted cities in United States, June 2025
644 cities in United States ranked by their average PM2.5 over the 30 days. Worst: Oconomowoc at 20.4 µg/m³, #141 of 1,912 cities in the world. Cleanest: Mount Vernon at 2.0. A city needs measurements on 70% of the days to be ranked.
- 1Oconomowoclow-cost sensorsWisconsin 20.4
- 2DoltonIllinois 17.8
- 2BismarckNorth Dakota 17.8
- 4CalexicoCalifornia 17.4
- 5Franklin ParkIllinois 17.3
- 6BridgeviewIllinois 16.9
- 6RedfordMichigan 16.9
- 6OregonOhio 16.9
- 9Wake Forestlow-cost sensorsNorth Carolina 16.8
- 10JolietIllinois 16.7
- 10GaryIndiana 16.7
- 10HammondIndiana 16.7
- 13West FargoNorth Dakota 16.5
- 14Pasadenalow-cost sensorsCalifornia 16.2
- 15ChicagoIllinois 16.1
- 15Elmwood ParkIllinois 16.1
- 17NapervilleIllinois 16.0
- 18Des PlainesIllinois 15.9
- 18WyomingMichigan 15.9
- 18MinneapolisMinnesota 15.9
- 18FontanaCalifornia 15.9
- 22Michigan CityIndiana 15.8
- 22BrookingsSouth Dakota 15.8
- 22WheelingWest Virginia 15.8
- 25PeoriaIllinois 15.7
- 25DuluthMinnesota 15.7
- 27DearbornMichigan 15.6
- 28Calumet CityIllinois 15.4
- 28KalamazooMichigan 15.4
- 28PerrysburgOhio 15.4
- 31Oak LawnIllinois 15.3
- 32Santa Monicalow-cost sensorsCalifornia 15.2
- 33Columbialow-cost sensorsMissouri 15.1
- 33BlaineMinnesota 15.1
- 35Apple ValleyMinnesota 15.0
- 35RochesterMinnesota 15.0
- 35SteubenvilleOhio 15.0
- 38ElginIllinois 14.9
- 39DetroitMichigan 14.8
- 39MankatoMinnesota 14.8
- 39ShakopeeMinnesota 14.8
- 39WestervilleOhio 14.8
- 39Eau ClaireWisconsin 14.8
- 44BurnsvilleMinnesota 14.7
- 45West MifflinPennsylvania 14.6
- 46Cedar RapidsIowa 14.5
- 46East ChicagoIndiana 14.5
- 46Port HuronMichigan 14.5
- 46SouthfieldMichigan 14.5
- 46MilwaukeeWisconsin 14.5
- 46Los AngelesCalifornia 14.5
- 52CaryIllinois 14.4
- 52PortageIndiana 14.4
- 54ColumbusOhio 14.3
- 54AuroraIllinois 14.3
- 54Grand RapidsMichigan 14.3
- 54Lincoln ParkMichigan 14.3
- 54MadisonWisconsin 14.3
- 59South BendIndiana 14.2
- 60Iowa CityIowa 14.1
- 60Jurupa ValleyCalifornia 14.1
- 62FishersIndiana 13.9
- 62HollandMichigan 13.9
- 62TaylorMichigan 13.9
- 65MiddletownOhio 13.8
- 65RockfordIllinois 13.8
- 65ToledoOhio 13.8
- 65AltoonaPennsylvania 13.8
- 65BadgerAlaska 13.8
- 70Terre HauteIndiana 13.7
- 70DavenportIowa 13.7
- 70YpsilantiMichigan 13.7
- 70Green BayWisconsin 13.7
- 70SuperiorWisconsin 13.7
- 70WaukeshaWisconsin 13.7
- 70RiversideCalifornia 13.7
- 77NorthbrookIllinois 13.6
- 77MarquetteMichigan 13.6
- 77AppletonWisconsin 13.6
- 80ClintonIowa 13.5
- 80LansingMichigan 13.5
- 80Saint MichaelMinnesota 13.5
- 83IndianapolisIndiana 13.4
- 83ElkhartIndiana 13.4
- 83ClevelandOhio 13.4
- 83GlendoraCalifornia 13.4
- 87PortsmouthOhio 13.3
- 87SpringfieldOhio 13.3
- 87EastpointeMichigan 13.3
- 87CantonOhio 13.3
- 91ChampaignIllinois 13.2
- 92BloomingtonIllinois 13.1
- 92Fort WayneIndiana 13.1
- 92MuncieIndiana 13.1
- 92LimaOhio 13.1
- 96PittsburghPennsylvania 13.0
- 97Saint JosephMissouri 12.9
- 97BrookfieldIllinois 12.9
- 97MolineIllinois 12.9
- 97WarrenOhio 12.9
- 101DaytonOhio 12.8
- 102ZionIllinois 12.7
- 102BurbankCalifornia 12.7
- 102SocorroTexas 12.7
- 105HoustonTexas 12.6
- 105Des MoinesIowa 12.6
- 105WaterlooIowa 12.6
- 105Bay CityMichigan 12.6
- 109Upper AltonIllinois 12.5
- 109JenisonMichigan 12.5
- 111SpringfieldIllinois 12.4
- 112DecaturIllinois 12.3
- 112NorwoodOhio 12.3
- 112ElizabethNew Jersey 12.3
- 115East Saint LouisIllinois 12.2
- 115CincinnatiOhio 12.2
- 115LafayetteIndiana 12.2
- 115YoungstownOhio 12.2
- 115Santa ClaritaCalifornia 12.2
- 120AlbanyNew York 12.0
- 120BuffaloNew York 12.0
- 120South MilwaukeeWisconsin 12.0
- 123Santa BarbaraCalifornia 11.9
- 124Corpus ChristiTexas 11.8
- 124WeirtonWest Virginia 11.8
- 126HartfordConnecticut 11.7
- 126AndersonIndiana 11.7
- 128JasperIndiana 11.6
- 128AnkenyIowa 11.6
- 128PaysonArizona 11.6
- 131Granite CityIllinois 11.5
- 132GainesvilleGeorgia 11.4
- 132SewellNew Jersey 11.4
- 132Cleveland HeightsOhio 11.4
- 132PortlandMaine 11.4
- 132Shaker HeightsOhio 11.4
- 132Lake ElsinoreCalifornia 11.4
- 132HelenaMontana 11.4
- 132MillcreekUtah 11.4
- 140MaconGeorgia 11.3
- 140MuscatineIowa 11.3
- 140Saint CloudMinnesota 11.3
- 140AkronOhio 11.3
- 140DublinOhio 11.3
- 140HarrisburgPennsylvania 11.3
- 140McKeesportPennsylvania 11.3
- 140WilkinsburgPennsylvania 11.3
- 140BakersfieldCalifornia 11.3
- 140BanningCalifornia 11.3
- 150WilmingtonDelaware 11.2
- 150EdinburgTexas 11.2
- 150New York CityNew York 11.2
- 150AnaheimCalifornia 11.2
- 150IndioCalifornia 11.2
- 150San DiegoCalifornia 11.2
- 156ColumbusIndiana 11.1
- 156LouisvilleKentucky 11.1
- 156PennsaukenNew Jersey 11.1
- 156PhiladelphiaPennsylvania 11.1
- 156East RidgeTennessee 11.1
- 156CarlislePennsylvania 11.1
- 156BrawleyCalifornia 11.1
- 156ComptonCalifornia 11.1
- 156Cedar CityUtah 11.1
- 156Great FallsMontana 11.1
- 166West MemphisArkansas 11.0
- 166BloomingtonIndiana 11.0
- 166HuntingtonWest Virginia 11.0
- 166BostonMassachusetts 11.0
- 166EwingNew Jersey 11.0
- 166MedinaOhio 11.0
- 166PainesvilleOhio 11.0
- 166LebanonPennsylvania 11.0
- 174OwensboroKentucky 10.9
- 174SpringfieldMassachusetts 10.9
- 174FairbanksAlaska 10.9
- 177Little RockArkansas 10.8
- 177EvansvilleIndiana 10.8
- 177JeffersonvilleIndiana 10.8
- 177BaytownTexas 10.8
- 177DanburyConnecticut 10.8
- 177BerkeleyCalifornia 10.8
- 183DoverDelaware 10.7
- 183Valley StationKentucky 10.7
- 183ConroeTexas 10.7
- 183Jersey CityNew Jersey 10.7
- 183EriePennsylvania 10.7
- 183El PasoTexas 10.7
- 189Bonita SpringsFlorida 10.6
- 189LexingtonNorth Carolina 10.6
- 189Roanoke RapidsNorth Carolina 10.6
- 189South VinelandNew Jersey 10.6
- 189ChattanoogaTennessee 10.6
- 189WorcesterMassachusetts 10.6
- 189El CajonCalifornia 10.6
- 189VictorvilleCalifornia 10.6
- 197Ponte Vedra BeachFlorida 10.5
- 197EdgewoodMaryland 10.5
- 197St. LouisMissouri 10.5
- 197BrownsvilleTexas 10.5
- 197RochesterNew York 10.5
- 197ScrantonPennsylvania 10.5
- 197State CollegePennsylvania 10.5
- 197Spanish ForkUtah 10.5
- 205WashingtonDistrict of Columbia 10.4
- 205SpartanburgSouth Carolina 10.4
- 205KnoxvilleTennessee 10.4
- 205LindenNew Jersey 10.4
- 205GahannaOhio 10.4
- 205Sioux FallsSouth Dakota 10.4
- 205WatertownSouth Dakota 10.4
- 205PowayCalifornia 10.4
- 205Sunland ParkNew Mexico 10.4
- 214LemayMissouri 10.3
- 214YorkPennsylvania 10.3
- 214MissionTexas 10.3
- 214New HavenConnecticut 10.3
- 214FraminghamMassachusetts 10.3
- 214GreenfieldMassachusetts 10.3
- 220VeniceFlorida 10.2
- 220JacksonTennessee 10.2
- 220LaredoTexas 10.2
- 220PortervilleCalifornia 10.2
- 224LowellMassachusetts 10.1
- 224New BrunswickNew Jersey 10.1
- 224PatersonNew Jersey 10.1
- 224RutlandVermont 10.1
- 224Long BeachCalifornia 10.1
- 224Simi ValleyCalifornia 10.1
- 230BirminghamAlabama 10.0
- 230NewarkDelaware 10.0
- 230AtlantaGeorgia 10.0
- 230Saint MatthewsKentucky 10.0
- 230JacksonMississippi 10.0
- 230La PorteTexas 10.0
- 230WaterburyConnecticut 10.0
- 230Fort LeeNew Jersey 10.0
- 230JohnstownPennsylvania 10.0
- 230LancasterPennsylvania 10.0
- 230Weirton HeightsWest Virginia 10.0
- 241ScaggsvilleMaryland 9.9
- 241ClaytonNorth Carolina 9.9
- 241NashvilleTennessee 9.9
- 241Mission BendTexas 9.9
- 241San AntonioTexas 9.9
- 241PittsfieldMassachusetts 9.9
- 241HermitagePennsylvania 9.9
- 241San JoseCalifornia 9.9
- 241WoodlandCalifornia 9.9
- 250PaducahKentucky 9.8
- 250GadsdenAlabama 9.8
- 250OlatheKansas 9.8
- 250Atlantic CityNew Jersey 9.8
- 250HendersonvilleTennessee 9.8
- 250AustinTexas 9.8
- 250Live OakTexas 9.8
- 250TexarkanaTexas 9.8
- 250AshburnVirginia 9.8
- 250LynnMassachusetts 9.8
- 250North ChicopeeMassachusetts 9.8
- 250OmahaNebraska 9.8
- 250TrentonNew Jersey 9.8
- 250VisaliaCalifornia 9.8
- 264JeffersontownKentucky 9.7
- 264BartlettTennessee 9.7
- 264GalvestonTexas 9.7
- 264PortsmouthNew Hampshire 9.7
- 264SyracuseNew York 9.7
- 264BridgeportConnecticut 9.7
- 264NipomoCalifornia 9.7
- 264Candler-McAfeeGeorgia 9.7
- 272ValdostaGeorgia 9.6
- 272TopekaKansas 9.6
- 272FayettevilleNorth Carolina 9.6
- 272HickoryNorth Carolina 9.6
- 272LebanonOhio 9.6
- 272West JordanUtah 9.6
- 272Oxon Hill-GlassmanorMaryland 9.6
- 272MidwayFlorida 9.6
- 280TallahasseeFlorida 9.5
- 280AugustaGeorgia 9.5
- 280PleasantvilleNew Jersey 9.5
- 280Oklahoma CityOklahoma 9.5
- 280Saint AndrewsSouth Carolina 9.5
- 280KingsportTennessee 9.5
- 280CorcoranCalifornia 9.5
- 280RichmondCalifornia 9.5
- 280Eagle PassTexas 9.5
- 289BearDelaware 9.4
- 289MiamiFlorida 9.4
- 289LawrencevilleGeorgia 9.4
- 289RaleighNorth Carolina 9.4
- 289DyersburgTennessee 9.4
- 289San MarcosTexas 9.4
- 289SpringfieldVirginia 9.4
- 289QuincyMassachusetts 9.4
- 289KeeneNew Hampshire 9.4
- 289NorristownPennsylvania 9.4
- 289ProvidenceRhode Island 9.4
- 289Thousand OaksCalifornia 9.4
- 301AshlandKentucky 9.3
- 301Lexington-FayetteKentucky 9.3
- 301New OrleansLouisiana 9.3
- 301BaltimoreMaryland 9.3
- 301ElktonMaryland 9.3
- 301EssexMaryland 9.3
- 301ArnoldMissouri 9.3
- 301FlorenceSouth Carolina 9.3
- 301GreenvilleSouth Carolina 9.3
- 301ChesapeakeVirginia 9.3
- 301KokomoIndiana 9.3
- 301MilfordMassachusetts 9.3
- 301AllentownPennsylvania 9.3
- 301BethlehemPennsylvania 9.3
- 301ReadingPennsylvania 9.3
- 301Las CrucesNew Mexico 9.3
- 317DerbyKansas 9.2
- 317Baton RougeLouisiana 9.2
- 317CharlotteNorth Carolina 9.2
- 317North CharlestonSouth Carolina 9.2
- 317Missouri CityTexas 9.2
- 317Lexingtonlow-cost sensorsMassachusetts 9.2
- 317UticaNew York 9.2
- 317OaklandCalifornia 9.2
- 317OxnardCalifornia 9.2
- 317RandolphNew Jersey 9.2
- 327HuntsvilleAlabama 9.1
- 327Warner RobinsGeorgia 9.1
- 327University CityMissouri 9.1
- 327MorrisvilleNorth Carolina 9.1
- 327MaryvilleTennessee 9.1
- 327Port ArthurTexas 9.1
- 327OceansideCalifornia 9.1
- 327Santa PaulaCalifornia 9.1
- 335AlbanyGeorgia 9.0
- 335ColumbusGeorgia 9.0
- 335RoanokeVirginia 9.0
- 335New LondonConnecticut 9.0
- 335LincolnNebraska 9.0
- 335HanfordCalifornia 9.0
- 341HueytownAlabama 8.9
- 341Fort LauderdaleFlorida 8.9
- 341HagerstownMaryland 8.9
- 341ClemmonsNorth Carolina 8.9
- 341Toms RiverNew Jersey 8.9
- 341MasonOhio 8.9
- 341ClarksvilleTennessee 8.9
- 341HarrisonburgVirginia 8.9
- 341HaverhillMassachusetts 8.9
- 341Grand IslandNebraska 8.9
- 351DecaturAlabama 8.8
- 351MontgomeryAlabama 8.8
- 351Fort ThomasKentucky 8.8
- 351LafayetteLouisiana 8.8
- 351Kansas CityMissouri 8.8
- 351DurhamNorth Carolina 8.8
- 351GreenvilleNorth Carolina 8.8
- 351White OakOhio 8.8
- 351Rose HillVirginia 8.8
- 351Arroyo GrandeCalifornia 8.8
- 361SpringdaleArkansas 8.7
- 361ChesterPennsylvania 8.7
- 361CharlottesvilleVirginia 8.7
- 361HolbrookNew York 8.7
- 361PawtucketRhode Island 8.7
- 361El CentroCalifornia 8.7
- 361OremUtah 8.7
- 368ElizabethtownKentucky 8.6
- 368GreensboroNorth Carolina 8.6
- 368Fall RiverMassachusetts 8.6
- 368AberdeenSouth Dakota 8.6
- 368MaderaCalifornia 8.6
- 373McDonoughGeorgia 8.5
- 373NicholasvilleKentucky 8.5
- 373KennerLouisiana 8.5
- 373LibertyMissouri 8.5
- 373GulfportMississippi 8.5
- 373CorsicanaTexas 8.5
- 373DentonTexas 8.5
- 373RichmondVirginia 8.5
- 373DerryNew Hampshire 8.5
- 373FillmoreCalifornia 8.5
- 373LompocCalifornia 8.5
- 373AnacortesWashington 8.5
- 385TrussvilleAlabama 8.4
- 385ChalmetteLouisiana 8.4
- 385East HamptonVirginia 8.4
- 385NewburghNew York 8.4
- 385HurricaneUtah 8.4
- 385TooeleUtah 8.4
- 391PrichardAlabama 8.3
- 391Delray BeachFlorida 8.3
- 391HomesteadFlorida 8.3
- 391Oak RidgeFlorida 8.3
- 391Palm CityFlorida 8.3
- 391LeawoodKansas 8.3
- 391CharlestonWest Virginia 8.3
- 391FolsomCalifornia 8.3
- 391GaltCalifornia 8.3
- 400AthensGeorgia 8.2
- 400AshevilleNorth Carolina 8.2
- 400BeltonTexas 8.2
- 400College StationTexas 8.2
- 400Short PumpVirginia 8.2
- 400AugustaMaine 8.2
- 400BellevueNebraska 8.2
- 400New CityNew York 8.2
- 400San LeandroCalifornia 8.2
- 400HobbsNew Mexico 8.2
- 410DavieFlorida 8.1
- 410ValricoFlorida 8.1
- 410SavannahGeorgia 8.1
- 410HernandoMississippi 8.1
- 410Fort WorthTexas 8.1
- 410BrocktonMassachusetts 8.1
- 410La VistaNebraska 8.1
- 410White PlainsNew York 8.1
- 410RosevilleCalifornia 8.1
- 410San FranciscoCalifornia 8.1
- 410StocktonCalifornia 8.1
- 421FairhopeAlabama 8.0
- 421Daytona BeachFlorida 8.0
- 421PascagoulaMississippi 8.0
- 421CookevilleTennessee 8.0
- 421LewistonMaine 8.0
- 421GilroyCalifornia 8.0
- 421Arvadalow-cost sensorsColorado 8.0
- 421OdessaTexas 8.0
- 421Rapid CitySouth Dakota 8.0
- 430BrunswickGeorgia 7.9
- 430TulsaOklahoma 7.9
- 430ColumbiaTennessee 7.9
- 430HerrimanUtah 7.9
- 430West Valley CityUtah 7.9
- 435Deerfield BeachFlorida 7.8
- 435JacksonvilleFlorida 7.8
- 435South LaurelMaryland 7.8
- 435HattiesburgMississippi 7.8
- 435MooreOklahoma 7.8
- 435BangorMaine 7.8
- 435DavisCalifornia 7.8
- 435SalinasCalifornia 7.8
- 435Four CornersFlorida 7.8
- 444Ferry PassFlorida 7.7
- 444GainesvilleFlorida 7.7
- 444VallejoCalifornia 7.7
- 447TampaFlorida 7.6
- 447Hunt ValleyMaryland 7.6
- 447NogalesArizona 7.6
- 447YumaArizona 7.6
- 447FresnoCalifornia 7.6
- 447North OgdenUtah 7.6
- 447Salt Lake CityUtah 7.6
- 454Belle GladeFlorida 7.5
- 454Fort MyersFlorida 7.5
- 454St. PetersburgFlorida 7.5
- 454SulphurLouisiana 7.5
- 454RaymoreMissouri 7.5
- 454ChicoCalifornia 7.5
- 454MartinezCalifornia 7.5
- 454PleasantonCalifornia 7.5
- 454BillingsMontana 7.5
- 463Fruit CoveFlorida 7.4
- 463OrlandoFlorida 7.4
- 463Winston-SalemNorth Carolina 7.4
- 463TucsonArizona 7.4
- 463LincolnCalifornia 7.4
- 463BountifulUtah 7.4
- 469Coconut CreekFlorida 7.3
- 469ConwaySouth Carolina 7.3
- 469Yuba CityCalifornia 7.3
- 472BessemerAlabama 7.2
- 473West PensacolaFlorida 7.1
- 473New AlbanyIndiana 7.1
- 473RockvilleMaryland 7.1
- 473Ponca CityOklahoma 7.1
- 473ThorntonColorado 7.1
- 473Brigham CityUtah 7.1
- 473HighlandUtah 7.1
- 480SaginawTexas 7.0
- 481Lake MaryFlorida 6.9
- 481WestonFlorida 6.9
- 481LivermoreCalifornia 6.9
- 481LongmontColorado 6.9
- 481LewistonIdaho 6.9
- 486San Luis ObispoCalifornia 6.8
- 486Dodge CityKansas 6.8
- 486RexburgIdaho 6.8
- 489Safety HarborFlorida 6.7
- 489LawtonOklahoma 6.7
- 489HopewellVirginia 6.7
- 489Redwood CityCalifornia 6.7
- 489ReddingCalifornia 6.7
- 489BozemanMontana 6.7
- 495WellingtonFlorida 6.6
- 495McAlesterOklahoma 6.6
- 495ClovisCalifornia 6.6
- 498CoventryRhode Island 6.5
- 498HollisterCalifornia 6.5
- 498Fort CollinsColorado 6.5
- 501SarasotaFlorida 6.4
- 501RidgecrestCalifornia 6.4
- 501SacramentoCalifornia 6.4
- 501TracyCalifornia 6.4
- 501DenverColorado 6.4
- 501Las VegasNevada 6.4
- 501GreeleyColorado 6.4
- 501MoscowIdaho 6.4
- 501MagnaUtah 6.4
- 510Casas AdobesArizona 6.3
- 510LancasterCalifornia 6.3
- 510Picnic Point-North LynnwoodWashington 6.3
- 513SpringfieldMissouri 6.2
- 513LaconiaNew Hampshire 6.2
- 513PhoenixArizona 6.2
- 513MercedCalifornia 6.2
- 513Santa CruzCalifornia 6.2
- 513AlbuquerqueNew Mexico 6.2
- 513RenoNevada 6.2
- 513BoulderColorado 6.2
- 521East LakeFlorida 6.1
- 521ShreveportLouisiana 6.1
- 521JenksOklahoma 6.1
- 521GlendaleArizona 6.1
- 521ModestoCalifornia 6.1
- 521LubbockTexas 6.1
- 521Summerlin SouthNevada 6.1
- 528Casa GrandeArizona 6.0
- 528FlagstaffArizona 6.0
- 528MantecaCalifornia 6.0
- 528ParadiseCalifornia 6.0
- 528San RafaelCalifornia 6.0
- 528TurlockCalifornia 6.0
- 528UkiahCalifornia 6.0
- 528WindsorColorado 6.0
- 536EnterpriseNevada 5.9
- 536Columbia CityWashington 5.9
- 538MesaArizona 5.8
- 538PuebloColorado 5.8
- 538WenatcheeWashington 5.8
- 541OrcuttCalifornia 5.7
- 541Spring ValleyNevada 5.7
- 541GilletteWyoming 5.7
- 544Palm BayFlorida 5.5
- 544Palo Altolow-cost sensorsCalifornia 5.5
- 544PocatelloIdaho 5.5
- 544SeattleWashington 5.5
- 544SunnysideWashington 5.5
- 544CasperWyoming 5.5
- 550TempeArizona 5.4
- 550Rio RanchoNew Mexico 5.4
- 550HermistonOregon 5.4
- 550Rock SpringsWyoming 5.4
- 550SheridanWyoming 5.4
- 555MaranaArizona 5.3
- 555TruckeeCalifornia 5.3
- 555HendersonNevada 5.3
- 555MesquiteNevada 5.3
- 555CondaIdaho 5.3
- 560ConcordCalifornia 5.2
- 560Cañon CityColorado 5.2
- 562EdmondOklahoma 5.1
- 562Ken CarylColorado 5.1
- 562NampaIdaho 5.1
- 562ButteMontana 5.1
- 562Moses LakeWashington 5.1
- 562Port AngelesWashington 5.1
- 562Spokane ValleyWashington 5.1
- 569Fort SmithArkansas 5.0
- 569TacomaWashington 5.0
- 571EugeneOregon 4.9
- 571AuburnWashington 4.9
- 573VacavilleCalifornia 4.8
- 573Boulder CityNevada 4.8
- 573TigardOregon 4.8
- 573SpokaneWashington 4.8
- 577Coeur d'AleneIdaho 4.7
- 577MedfordOregon 4.7
- 577BellinghamWashington 4.7
- 577YakimaWashington 4.7
- 581Winter ParkFlorida 4.6
- 581Idaho FallsIdaho 4.6
- 581BremertonWashington 4.6
- 584Grand JunctionColorado 4.5
- 584MeridianIdaho 4.5
- 584Twin FallsIdaho 4.5
- 584LaramieWyoming 4.5
- 588LittletonColorado 4.4
- 588Apache JunctionArizona 4.4
- 588RentonWashington 4.4
- 588ShorelineWashington 4.4
- 592EllensburgWashington 4.3
- 593LaceyWashington 4.2
- 594Spanish SpringsNevada 4.1
- 594CanbyOregon 4.1
- 594BurienWashington 4.1
- 597BoiseIdaho 4.0
- 597The DallesOregon 4.0
- 599Green ValleyArizona 3.9
- 599Walla WallaWashington 3.9
- 601Santa RosaCalifornia 3.8
- 601AshlandOregon 3.8
- 601SalemOregon 3.8
- 601AberdeenWashington 3.8
- 601HonoluluHawaii 3.8
- 606BendOregon 3.7
- 606PortlandOregon 3.7
- 606ParklandWashington 3.7
- 606PullmanWashington 3.7
- 606Salmon CreekWashington 3.7
- 606CheyenneWyoming 3.7
- 612BellevueWashington 3.6
- 612KahuluiHawaii 3.6
- 614Carson CityNevada 3.5
- 614MilwaukieOregon 3.5
- 614Oregon CityOregon 3.5
- 614VancouverWashington 3.5
- 614KīheiHawaii 3.5
- 614Makakilo / Kapolei / Honokai HaleHawaii 3.5
- 620Grants PassOregon 3.4
- 620RedmondOregon 3.4
- 620CentraliaWashington 3.4
- 623AlbanyOregon 3.3
- 623LongviewWashington 3.3
- 625AltamontOregon 3.2
- 625PendletonOregon 3.2
- 625RoseburgOregon 3.2
- 625HiloHawaii 3.2
- 629MissoulaMontana 3.1
- 629BeavertonOregon 3.1
- 629WoodburnOregon 3.1
- 629Inglewood-Finn Hilllow-cost sensorsWashington 3.1
- 629Tri-CitiesWashington 3.1
- 634GreshamOregon 3.0
- 634HillsboroOregon 3.0
- 636McMinnvilleOregon 2.8
- 636AnchorageAlaska 2.8
- 638Coos BayOregon 2.7
- 639DallasOregon 2.6
- 640CorvallisOregon 2.4
- 640Forest GroveOregon 2.4
- 642Oak HarborWashington 2.2
- 643AtascaderoCalifornia 2.1
- 644Mount VernonWashington 2.0
Good0–9.0
Moderate9.1–35.4
Sensitive groups35.5–55.4
Unhealthy55.5–125.4
Very unhealthy125.5–225.4
Hazardous225.5+