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.

=3096GlashüttenHesse, Germany 0%0 of 29
=3096KeeneNew Hampshire, United States 0%0 of 30
=3096Holbrooklast full day 11 OctNew York, United States 0%0 of 28
=3096NorristownPennsylvania, United States 0%0 of 28
=3096PuebloColorado, United States 0%0 of 24
=3096Carson CityNevada, United States 0%0 of 30
=3096EphrataWashington, United States 0%0 of 24
=3096BellevilleOntario, Canada 0%0 of 30
=3096CrestonBritish Columbia, Canada 0%0 of 29
=3096Grande PrairieAlberta, Canada 0%0 of 30
=3096EdertalHesse, Germany 0%0 of 29
=3112PoriSatakunta, Finland 0%0 of 30
=3112KamaishiIwate, Japan 0%0 of 30
=3112BrayLeinster, Ireland 0%0 of 30
=3112Palm BayFlorida, United States 0%0 of 30
=3112LynnMassachusetts, United States 0%0 of 30
=3112North AdamsMassachusetts, United States 0%0 of 30
=3112PortlandMaine, United States 0%0 of 30
=3112CloquetMinnesota, United States 0%0 of 30
=3112DuluthMinnesota, United States 0%0 of 30
=3112Albanylast full day 11 OctNew York, United States 0%0 of 26
=3112ProvidenceRhode Island, United States 0%0 of 30
=3112ArvadaColorado, United States 0%0 of 30
=3112EnterpriseNevada, United States 0%0 of 30
=3112Oregon CityOregon, United States 0%0 of 28
=3112Mount VernonWashington, United States 0%0 of 30
=3112AllistonOntario, Canada 0%0 of 29
=3112DrummondvilleQuebec, Canada 0%0 of 30
=3112Miltonlast full day 9 OctOntario, Canada 0%0 of 25
=3112Port AlberniBritish Columbia, Canada 0%0 of 24
=3112High PeakEngland, United Kingdom 0%0 of 30
=3112KallahtiUusimaa, Finland 0%0 of 30
=3133Saint-PaulReunion, Reunion 0%0 of 30
=3133KujiIwate, Japan 0%0 of 27
=3133WrexhamWales, United Kingdom 0%0 of 30
=3133PickeringEngland, United Kingdom 0%0 of 30
=3133OxfordEngland, United Kingdom 0%0 of 30
=3133AurillacAuvergne-Rhône-Alpes, France 0%0 of 30
=3133FrostburgMaryland, United States 0%0 of 27
=3133PaulsboroNew Jersey, United States 0%0 of 30
=3133GreenfieldMassachusetts, United States 0%0 of 30
=3133UxbridgeMassachusetts, United States 0%0 of 28
=3133AugustaMaine, United States 0%0 of 30
=3133MarquetteMichigan, United States 0%0 of 30
=3133BlairNebraska, United States 0%0 of 23
=3133PortsmouthNew Hampshire, United States 0%0 of 30
=3133LompocCalifornia, United States 0%0 of 29
=3133HendersonNevada, United States 0%0 of 30
=3133Spring ValleyNevada, United States 0%0 of 30
=3133Hood RiverOregon, United States 0%0 of 30
=3133McMinnvilleOregon, United States 0%0 of 28
=3133VernalUtah, United States 0%0 of 30
=3133Hilolast full day 11 OctHawaii, United States 0%0 of 28
=3133AnchorageAlaska, United States 0%0 of 30
=3133KingstonOntario, Canada 0%0 of 30
=3133NepeanOntario, Canada 0%0 of 30
=3133WhistlerBritish Columbia, Canada 0%0 of 27
=3158HedemoraDalarna, Sweden 0%0 of 27
=3158KillarneyMunster, Ireland 0%0 of 30
=3158CorteCorsica, France 0%0 of 29
=3158New LondonConnecticut, United States 0%0 of 30
=3158PittsfieldMassachusetts, United States 0%0 of 30
=3158WorcesterMassachusetts, United States 0%0 of 30
=3158ManisteeMichigan, United States 0%0 of 30
=3158Uticalast full day 11 OctNew York, United States 0%0 of 26
=3158VermillionSouth Dakota, United States 0%0 of 29
=3158BrookfieldWisconsin, United States 0%0 of 23
=3158DeltaColorado, United States 0%0 of 28
=3158LittletonColorado, United States 0%0 of 28
=3158OttawaOntario, Canada 0%0 of 30
=3158Sept-ÎlesQuebec, Canada 0%0 of 30
=3172OuluNorth Ostrobothnia, Finland 0%0 of 27
=3172FraminghamMassachusetts, United States 0%0 of 30
=3172LondonderryNew Hampshire, United States 0%0 of 30
=3172BurlingtonVermont, United States 0%0 of 30
=3172MaranaArizona, United States 0%0 of 30
=3172PriceUtah, United States 0%0 of 30
=3172MissoulaMontana, United States 0%0 of 30
=3172PierreSouth Dakota, United States 0%0 of 28
=3172North BayOntario, Canada 0%0 of 28
=3172SaguenayQuebec, Canada 0%0 of 30
=3172Saint John EastNew Brunswick, Canada 0%0 of 30
=3172SherbrookeQuebec, Canada 0%0 of 30
=3172Summerlin SouthNevada, United States 0%0 of 28
=3185LahtiPaijat-Hame, Finland 0%0 of 30
=3185HämeenkyläUusimaa, Finland 0%0 of 30
=3185AdelaideSouth Australia, Australia 0%0 of 25
=3185ChepstowWales, United Kingdom 0%0 of 30
=3185Vila RealVila Real, Portugal 0%0 of 30
=3185OlpeNorth Rhine-Westphalia, Germany 0%0 of 30
=3185GersfeldHesse, Germany 0%0 of 29
=3185Haverhilllast full day 9 OctMassachusetts, United States 0%0 of 25
=3185WareMassachusetts, United States 0%0 of 30
=3185HartfordVermont, United States 0%0 of 30
=3185Ken CarylColorado, United States 0%0 of 24
=3185South ValleyNew Mexico, United States 0%0 of 30
=3185BoulderColorado, United States 0%0 of 28
=3185CasperWyoming, United States 0%0 of 30
=3185GilletteWyoming, United States 0%0 of 29
=3185HonoluluHawaii, United States 0%0 of 30

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).