All 3,198 cities by unhealthy days, this year

Every city with enough measurements in this window, worst first.

CPCB in India: no readings since 12 Oct (488 monitors). EEA in Spain: no readings since 13 Oct (310 monitors). Their cities show older figures or are missing from this board, not clean.

Ranked by unhealthy days: the share of each city's measured days with a daily mean over 35.4 µg/m³ (US AQI 101+), Unhealthy for Sensitive Groups or worse on the US EPA's scale. Cities with the same share are ordered by more unhealthy days, then by the higher average.

=2892PikevilleKentucky, United States 0%0 of 282
=2892RaymoreMissouri, United States 0%0 of 282
=2892AlpineCalifornia, United States 0%0 of 286
=2892Redwood CityCalifornia, United States 0%0 of 260
=2892UkiahCalifornia, United States 0%0 of 269
=2892AlbuquerqueNew Mexico, United States 0%0 of 282
=2892Las VegasNevada, United States 0%0 of 286
=2892SeattleWashington, United States 0%0 of 286
=2892BécancourQuebec, Canada 0%0 of 279
=2910GeroGifu, Japan 0%0 of 272
=2910KatsuuraChiba, Japan 0%0 of 275
=2910TomakomaiHokkaido, Japan 0%0 of 278
=2910TownsvilleQueensland, Australia 0%0 of 285
=2910SeafordEngland, United Kingdom 0%0 of 210
=2910CarlisleEngland, United Kingdom 0%0 of 255
=2910BarnstapleEngland, United Kingdom 0%0 of 257
=2910Waldfischbach-Burgalbenlast full day 10 OctRheinland-Pfalz, Germany 0%0 of 271
=2910MallowMunster, Ireland 0%0 of 285
=2910Mo i RanaNordland, Norway 0%0 of 230
=2910São SebastiãoSão Paulo, Brazil 0%0 of 257
=2910Belle GladeFlorida, United States 0%0 of 258
=2910Sarasota SpringsFlorida, United States 0%0 of 281
=2910LafayetteLouisiana, United States 0%0 of 283
=2910KeeneNew Hampshire, United States 0%0 of 284
=2910El RioCalifornia, United States 0%0 of 281
=2910Palo AltoCalifornia, United States 0%0 of 284
=2910Rancho MurietaCalifornia, United States 0%0 of 280
=2910Fort CollinsColorado, United States 0%0 of 278
=2910Brigham CityUtah, United States 0%0 of 286
=2910MagnaUtah, United States 0%0 of 285
=2910Stansbury parkUtah, United States 0%0 of 286
=2932PoriSatakunta, Finland 0%0 of 259
=2932KamaishiIwate, Japan 0%0 of 278
=2932RockhamptonQueensland, Australia 0%0 of 278
=2932DunedinOtago, New Zealand 0%0 of 286
=2932SwindonEngland, United Kingdom 0%0 of 271
=2932ShrewsburyEngland, United Kingdom 0%0 of 276
=2932IrlamEngland, United Kingdom 0%0 of 214
=2932Flémalle-HauteWallonia, Belgium 0%0 of 285
=2932LimerickMunster, Ireland 0%0 of 285
=2932Cluain MealaMunster, Ireland 0%0 of 274
=2932BloisCentre-Val de Loire, France 0%0 of 283
=2932Villarejo de SalvanésMadrid, Spain 0%0 of 270
=2932Lake MaryFlorida, United States 0%0 of 279
=2932WellingtonFlorida, United States 0%0 of 265
=2932Fall RiverMassachusetts, United States 0%0 of 286
=2932MesaArizona, United States 0%0 of 280
=2932YrekaCalifornia, United States 0%0 of 280
=2932OttawaOntario, Canada 0%0 of 286
=2950BathurstNew South Wales, Australia 0%0 of 264
=2950AlmeríaAndalusia, Spain 0%0 of 263
=2950NaasLeinster, Ireland 0%0 of 276
=2950GreystonesLeinster, Ireland 0%0 of 285
=2950North AdamsMassachusetts, United States 0%0 of 286
=2950MarshallMinnesota, United States 0%0 of 279
=2950AtascaderoCalifornia, United States 0%0 of 278
=2950Gilroylast full day 11 OctCalifornia, United States 0%0 of 269
=2950North AuburnCalifornia, United States 0%0 of 281
=2950GlendiveMontana, United States 0%0 of 284
=2950HerrimanUtah, United States 0%0 of 277
=2950Albion Park RailNew South Wales, Australia 0%0 of 248
=2962BrisbaneQueensland, Australia 0%0 of 286
=2962LavertonVictoria, Australia 0%0 of 208
=2962WrexhamWales, United Kingdom 0%0 of 274
=2962StreetEngland, United Kingdom 0%0 of 206
=2962RoscommonConnacht, Ireland 0%0 of 262
=2962KillarneyMunster, Ireland 0%0 of 285
=2962BermeoBasque Country, Spain 0%0 of 283
=2962OsloOslo, Norway 0%0 of 255
=2962AugustaMaine, United States 0%0 of 278
=2962ReddingCalifornia, United States 0%0 of 281
=2962North OgdenUtah, United States 0%0 of 286
=2962Münstertal/SchwarzwaldBaden-Wurttemberg, Germany 0%0 of 272
=2962ŌshūIwate, Japan 0%0 of 277
=2975LappeenrantaSouth Karelia, Finland 0%0 of 286
=2975InaNagano, Japan 0%0 of 241
=2975MaryboroughQueensland, Australia 0%0 of 286
=2975AmoraSetúbal, Portugal 0%0 of 280
=2975Roetgenlast full day 10 OctNorth Rhine-Westphalia, Germany 0%0 of 282
=2975CavanUlster, Ireland 0%0 of 285
=2975CorteCorsica, France 0%0 of 243
=2975TelfordEngland, United Kingdom 0%0 of 276
=2975Palm BayFlorida, United States 0%0 of 282
=2975BangorMaine, United States 0%0 of 286
=2975ProvidenceRhode Island, United States 0%0 of 286
=2975HartfordVermont, United States 0%0 of 282
=2975ChicoCalifornia, United States 0%0 of 273
=2975ConcordCalifornia, United States 0%0 of 264
=2975OjaiCalifornia, United States 0%0 of 279
=2975Thousand OaksCalifornia, United States 0%0 of 275
=2975DenverColorado, United States 0%0 of 282
=2975LubbockTexas, United States 0%0 of 253
=2975AintreeVictoria, Australia 0%0 of 203
=2975KallahtiUusimaa, Finland 0%0 of 282
=2975Harewoodlast full day 4 OctBritish Columbia, Canada 0%0 of 256
=2996KushiroHokkaido, Japan 0%0 of 274
=2996GeelongVictoria, Australia 0%0 of 202
=2996GlasgowScotland, United Kingdom 0%0 of 209
=2996AberdeenScotland, United Kingdom 0%0 of 276
=2996Kirchzartenlast full day 9 OctBaden-Wurttemberg, Germany 0%0 of 263

What stands behind each figure: Checked at 2+ sites One reference monitor Low-cost sensors About these marks

Low-cost sensors: consumer units, counted only in cities with no government-grade monitor; they read close to reference monitors on the whole, but 15 to 25% high in humid air. How we use them.

Good0–50

Moderate51–100

Unhealthy for sensitive groups101–150

Unhealthy151–200

Very unhealthy201–300

Hazardous301+

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

Not covered: the government monitoring networks of China, Turkey and Iran, which publish only on their own websites. We are building the reader for China's network. The networks of Turkey and Iran don't answer requests from outside their countries, so we can't read them. Most cities there are missing from this board, not clean. Why.

Use this board

SmogRank, all cities ranked by unhealthy days (PM2.5), this year to 14 Oct 2026, 07:00 UTC: each city's share of its measured days with a daily mean over 35.4 µg/m³, cities measured on 70% or more of the days since 1 January (at least 14). Monitor data from national networks via OpenAQ and the publishers listed at smogrank.com/sources. smogrank.com/rankings?w=year&by=days. Ranked on low-cost sensors, with no reference monitor in the city: #4 Kampala and #8 Faisalabad. Some values from Sensor.Community, ODbL. Some readings from Department of Environment, Nepal; Vietnam's government monitors; Aurassure; RMCAB (Secretaría Distrital de Ambiente, Bogotá); Umhverfisstofnun (Environment Agency of Iceland), no reuse terms published.

Download top 10 by average (PNG)

You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.

Updated 2026-10-14 07:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index. Some low-cost readings: Sensor.Community, ODbL (data and licence). Some readings: Department of Environment, Nepal; Vietnam's government monitors; Aurassure; RMCAB (Secretaría Distrital de Ambiente, Bogotá); Umhverfisstofnun (Environment Agency of Iceland), no reuse terms published (why we use them).