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.

=2996GlashüttenHesse, Germany 0%0 of 279
=2996LewistonMaine, United States 0%0 of 277
=2996PortsmouthNew Hampshire, United States 0%0 of 281
=2996CrestlineCalifornia, United States 0%0 of 270
=2996Cedar Hillslast full day 11 OctUtah, United States 0%0 of 265
=2996BellinghamWashington, United States 0%0 of 282
=2996Port AngelesWashington, United States 0%0 of 226
=3008MorwellVictoria, Australia 0%0 of 212
=3008GoulburnNew South Wales, Australia 0%0 of 276
=3008MiddlesbroughEngland, United Kingdom 0%0 of 206
=3008HonitonEngland, United Kingdom 0%0 of 208
=3008SwordsLeinster, Ireland 0%0 of 274
=3008East LakeFlorida, United States 0%0 of 282
=3008Red Hilllast full day 5 OctSouth Carolina, United States 0%0 of 224
=3008EnochUtah, United States 0%0 of 278
=3008Crescent CityCalifornia, United States 0%0 of 223
=3008SherbrookeQuebec, Canada 0%0 of 281
=3018TartuTartu, Estonia 0%0 of 276
=3018GreenockScotland, United Kingdom 0%0 of 266
=3018GrangemouthScotland, United Kingdom 0%0 of 247
=3018SurseeLucerne, Switzerland 0%0 of 260
=3018NamurWallonia, Belgium 0%0 of 260
=3018Netphenlast full day 10 OctNorth Rhine-Westphalia, Germany 0%0 of 280
=3018Braunlagelast full day 10 OctLower Saxony, Germany 0%0 of 281
=3018RijekaPrimorje-Gorski Kotar, Croatia 0%0 of 228
=3018MarvinNorth Carolina, United States 0%0 of 254
=3018Casas AdobesArizona, United States 0%0 of 285
=3018TracyCalifornia, United States 0%0 of 278
=3018WillowsCalifornia, United States 0%0 of 285
=3018Colorado SpringsColorado, United States 0%0 of 275
=3018Spanish SpringsNevada, United States 0%0 of 281
=3018Red BluffCalifornia, United States 0%0 of 273
=3018SaguenayQuebec, Canada 0%0 of 283
=3018VictoriaBritish Columbia, Canada 0%0 of 269
=3035Uticalast full day 11 OctNew York, United States 0%0 of 265
=3035PawtucketRhode Island, United States 0%0 of 258
=3035AlamosaColorado, United States 0%0 of 272
=3035Saint-Jean-sur-RichelieuQuebec, Canada 0%0 of 279
=3035Picnic Point-North LynnwoodWashington, United States 0%0 of 280
=3035High PeakEngland, United Kingdom 0%0 of 206
=3041LahtiPaijat-Hame, Finland 0%0 of 266
=3041ChampionWallonia, Belgium 0%0 of 285
=3041Rabo de PeixeAzores, Portugal 0%0 of 274
=3041Newburghlast full day 11 OctNew York, United States 0%0 of 271
=3041Big Bear CityCalifornia, United States 0%0 of 282
=3041LamarColorado, United States 0%0 of 271
=3041PuebloColorado, United States 0%0 of 264
=3041WindsorColorado, United States 0%0 of 276
=3041GreenOregon, United States 0%0 of 264
=3041VancouverBritish Columbia, Canada 0%0 of 286
=3041MoranbahQueensland, Australia 0%0 of 286
=3041Logan CityQueensland, Australia 0%0 of 285
=3041Sunshine CoastQueensland, Australia 0%0 of 280
=3054Narvalast full day 10 OctIda-Virumaa, Estonia 0%0 of 276
=3054Santiago do Cacémlast full day 11 OctSetúbal, Portugal 0%0 of 215
=3054CheltenhamEngland, United Kingdom 0%0 of 261
=3054BrayLeinster, Ireland 0%0 of 277
=3054Grand IslandNebraska, United States 0%0 of 247
=3054BenningtonVermont, United States 0%0 of 282
=3054LancasterCalifornia, United States 0%0 of 286
=3054San RafaelCalifornia, United States 0%0 of 269
=3054Steamboat SpringsColorado, United States 0%0 of 257
=3054ShorelineWashington, United States 0%0 of 283
=3054BurnabyBritish Columbia, Canada 0%0 of 286
=3054DuncanBritish Columbia, Canada 0%0 of 204
=3054LangleyBritish Columbia, Canada 0%0 of 286
=3067KuopioNorth Savo, Finland 0%0 of 249
=3067EdinburghScotland, United Kingdom 0%0 of 204
=3067Presque IsleMaine, United States 0%0 of 286
=3067ParadiseCalifornia, United States 0%0 of 272
=3067North ValleyNew Mexico, United States 0%0 of 282
=3067Gardnerville RanchosNevada, United States 0%0 of 205
=3067Strawberry HillBritish Columbia, Canada 0%0 of 286
=3074GladstoneQueensland, Australia 0%0 of 286
=3074HedemoraDalarna, Sweden 0%0 of 231
=3074SolvangCalifornia, United States 0%0 of 279
=3074Heber CityUtah, United States 0%0 of 286
=3074BremertonWashington, United States 0%0 of 276
=3074LyndenWashington, United States 0%0 of 280
=3074KitimatBritish Columbia, Canada 0%0 of 280
=3081JyväskyläCentral Finland, Finland 0%0 of 250
=3081LourinhãLisbon, Portugal 0%0 of 247
=3081ÖrebroÖrebro, Sweden 0%0 of 280
=3081FolsomCalifornia, United States 0%0 of 284
=3081Los BanosCalifornia, United States 0%0 of 203
=3081TruckeeCalifornia, United States 0%0 of 282
=3081VacavilleCalifornia, United States 0%0 of 264
=3081Ken CarylColorado, United States 0%0 of 258
=3081Las CrucesNew Mexico, United States 0%0 of 271
=3081BoulderColorado, United States 0%0 of 279
=3081RichmondBritish Columbia, Canada 0%0 of 286
=3081Saint John EastNew Brunswick, Canada 0%0 of 285
=3081Ponta DelgadaAzores, Portugal 0%0 of 250
=3081Mango HillQueensland, Australia 0%0 of 286
=3081Tannum SandsQueensland, Australia 0%0 of 284
=3096ToowoombaQueensland, Australia 0%0 of 281
=3096CacémLisbon, Portugal 0%0 of 284
=3096GersfeldHesse, Germany 0%0 of 271
=3096ÅsaneVestland, Norway 0%0 of 241
=3096Sioux FallsSouth Dakota, United States 0%0 of 260

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).