All 3,290 cities by unhealthy days, last 30 days

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.

=2984State CollegePennsylvania, United States 0%0 of 30
=2984WarrenPennsylvania, United States 0%0 of 30
=2984RutlandVermont, United States 0%0 of 30
=2984BridgeportConnecticut, United States 0%0 of 30
=2984MesaArizona, United States 0%0 of 28
=2984LamarColorado, United States 0%0 of 28
=2984Idaho FallsIdaho, United States 0%0 of 29
=2984HillsboroOregon, United States 0%0 of 30
=2984PendletonOregon, United States 0%0 of 30
=2984PrinevilleOregon, United States 0%0 of 30
=2984EllensburgWashington, United States 0%0 of 30
=2984Liberty LakeWashington, United States 0%0 of 25
=2984SpokaneWashington, United States 0%0 of 30
=2984WenatcheeWashington, United States 0%0 of 30
=2984KahuluiHawaii, United States 0%0 of 27
=2984SarniaOntario, Canada 0%0 of 28
=2984Trois-RivièresQuebec, Canada 0%0 of 30
=2984Saint-GeorgesQuebec, Canada 0%0 of 28
=3019Castelló de la PlanaValencia, Spain 0%0 of 30
=3019Market DeepingEngland, United Kingdom 0%0 of 30
=3019HonitonEngland, United Kingdom 0%0 of 30
=3019ChristchurchEngland, United Kingdom 0%0 of 30
=3019BarnstapleEngland, United Kingdom 0%0 of 30
=3019Waldfischbach-Burgalbenlast full day 10 OctRheinland-Pfalz, Germany 0%0 of 27
=3019ColmarGrand Est, France 0%0 of 23
=3019SamaAsturias, Spain 0%0 of 30
=3019BenicàssimValencia, Spain 0%0 of 30
=3019BergenVestland, Norway 0%0 of 23
=3019Rabo de PeixeAzores, Portugal 0%0 of 30
=3019GlasgowDelaware, United States 0%0 of 30
=3019MarvinNorth Carolina, United States 0%0 of 30
=3019DanburyConnecticut, United States 0%0 of 30
=3019HartfordConnecticut, United States 0%0 of 30
=3019La VistaNebraska, United States 0%0 of 27
=3019BethlehemPennsylvania, United States 0%0 of 30
=3019EriePennsylvania, United States 0%0 of 30
=3019BarabooWisconsin, United States 0%0 of 30
=3019Colorado SpringsColorado, United States 0%0 of 26
=3019North ValleyNew Mexico, United States 0%0 of 30
=3019Gardnerville RanchosNevada, United States 0%0 of 24
=3019MoabUtah, United States 0%0 of 30
=3019PrestonIdaho, United States 0%0 of 30
=3019RoseburgOregon, United States 0%0 of 28
=3019BellevueWashington, United States 0%0 of 30
=3019FinleyWashington, United States 0%0 of 30
=3019SheltonWashington, United States 0%0 of 29
=3019Campbell RiverBritish Columbia, Canada 0%0 of 29
=3019MississaugaOntario, Canada 0%0 of 30
=3019Münstertal/SchwarzwaldBaden-Wurttemberg, Germany 0%0 of 30
=3019MizunashiFukushima, Japan 0%0 of 24
=3051LappeenrantaSouth Karelia, Finland 0%0 of 30
=3051BurwellEngland, United Kingdom 0%0 of 30
=3051ChampionWallonia, Belgium 0%0 of 30
=3051AnsWallonia, Belgium 0%0 of 29
=3051HalfwayMaryland, United States 0%0 of 30
=3051BostonMassachusetts, United States 0%0 of 30
=3051QuincyMassachusetts, United States 0%0 of 30
=3051New BrunswickNew Jersey, United States 0%0 of 30
=3051Rochesterlast full day 11 OctNew York, United States 0%0 of 28
=3051VacavilleCalifornia, United States 0%0 of 28
=3051BendOregon, United States 0%0 of 30
=3051Coos BayOregon, United States 0%0 of 30
=3051North PortlandOregon, United States 0%0 of 25
=3051AberdeenWashington, United States 0%0 of 30
=3051FairwoodWashington, United States 0%0 of 30
=3051KīheiHawaii, United States 0%0 of 30
=3051BécancourQuebec, Canada 0%0 of 30
=3051Greater SudburyOntario, Canada 0%0 of 30
=3051Tri-CitiesWashington, United States 0%0 of 30
=3070LohjaUusimaa, Finland 0%0 of 30
=3070ShrewsburyEngland, United Kingdom 0%0 of 30
=3070MiddlesbroughEngland, United Kingdom 0%0 of 30
=3070EdinburghScotland, United Kingdom 0%0 of 30
=3070AberdeenScotland, United Kingdom 0%0 of 30
=3070ÖrebroÖrebro, Sweden 0%0 of 28
=3070GroßalmerodeHesse, Germany 0%0 of 29
=3070SwordsLeinster, Ireland 0%0 of 30
=3070NaasLeinster, Ireland 0%0 of 30
=3070GreystonesLeinster, Ireland 0%0 of 30
=3070OviedoAsturias, Spain 0%0 of 30
=3070ShannonMunster, Ireland 0%0 of 30
=3070TelfordEngland, United Kingdom 0%0 of 30
=3070LowellMassachusetts, United States 0%0 of 30
=3070VirginiaMinnesota, United States 0%0 of 30
=3070West FargoNorth Dakota, United States 0%0 of 28
=3070Syracuselast full day 11 OctNew York, United States 0%0 of 28
=3070WatertownSouth Dakota, United States 0%0 of 28
=3070Casa GrandeArizona, United States 0%0 of 30
=3070Las CrucesNew Mexico, United States 0%0 of 29
=3070Heber CityUtah, United States 0%0 of 30
=3070MeadWashington, United States 0%0 of 30
=3070Port TownsendWashington, United States 0%0 of 30
=3070Fort St. JohnBritish Columbia, Canada 0%0 of 28
=3070GranbyQuebec, Canada 0%0 of 30
=3070Williams LakeBritish Columbia, Canada 0%0 of 29
=3096DunedinOtago, New Zealand 0%0 of 30
=3096KüssnachtSchwyz, Switzerland 0%0 of 29
=3096SundsvallVästernorrland, Sweden 0%0 of 25
=3096KarlstadVärmland, Sweden 0%0 of 26
=3096Netphenlast full day 10 OctNorth Rhine-Westphalia, Germany 0%0 of 26

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), last 30 days 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 21 or more of the 30 days. Monitor data from national networks via OpenAQ and the publishers listed at smogrank.com/sources. smogrank.com/rankings?w=30d&by=days. Ranked on low-cost sensors, with no reference monitor in the city: #1 Peshawar, #2 Multan, #5 Kasur, #7 Gujranwala, #8 Lahore, #9 Faisalabad and #10 Jammu. Some values from Sensor.Community, ODbL. Some readings from Vietnam's government monitors; Department of Environment, Nepal; Aurassure; RMCAB (Secretaría Distrital de Ambiente, Bogotá); Love My Air (City and County of Denver); 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: Vietnam's government monitors; Department of Environment, Nepal; Aurassure; RMCAB (Secretaría Distrital de Ambiente, Bogotá); Love My Air (City and County of Denver); Umhverfisstofnun (Environment Agency of Iceland), no reuse terms published (why we use them).