Cities With the Highest Ozone Right Now
Houston has the highest ground-level ozone concentration in our major-city sample right now, at about 154.0 µg/m³.
Cities with at least 200,000 residents; 100 cities shown.
Top Cities Ranked by Ozone (O3)
| # | City | Country | US AQI | PM2.5 | Ozone (O3) |
|---|---|---|---|---|---|
| 🥇 | Houston | United States | 63 | 15.4 µg/m³ | 154.0 µg/m³ |
| =2 | Mumbai | India | 157 | 64.7 µg/m³ | 151.0 µg/m³ |
| =2 | Thāne | India | 157 | 64.7 µg/m³ | 151.0 µg/m³ |
| 🥉 | Haikou | China | 117 | 42.1 µg/m³ | 148.0 µg/m³ |
| 4 | Dallas | United States | 51 | 9.2 µg/m³ | 142.0 µg/m³ |
| 5 | San Antonio | United States | 32 | 5.8 µg/m³ | 137.0 µg/m³ |
| 6 | Manaus | Brazil | 95 | 32.8 µg/m³ | 131.0 µg/m³ |
| 7 | Lusaka | Zambia | 76 | 22.4 µg/m³ | 114.0 µg/m³ |
| 8 | Muscat | Oman | 93 | 31.4 µg/m³ | 112.0 µg/m³ |
| =9 | Zapopan | Mexico | 14 | 2.6 µg/m³ | 106.0 µg/m³ |
| =9 | Guadalajara | Mexico | 14 | 2.6 µg/m³ | 106.0 µg/m³ |
| =10 | Belo Horizonte | Brazil | 34 | 6.2 µg/m³ | 105.0 µg/m³ |
| =10 | Maracaibo | Venezuela | 51 | 9.1 µg/m³ | 105.0 µg/m³ |
| =10 | Havana | Cuba | 54 | 10.7 µg/m³ | 105.0 µg/m³ |
| 11 | Goiânia | Brazil | 19 | 3.5 µg/m³ | 99.0 µg/m³ |
| 12 | Taipei | Taiwan | 56 | 11.9 µg/m³ | 98.0 µg/m³ |
| 13 | Singapore | Singapore | 63 | 15.4 µg/m³ | 95.0 µg/m³ |
| 14 | Harare | Zimbabwe | 100 | 35.4 µg/m³ | 93.0 µg/m³ |
| 15 | São Paulo | Brazil | 62 | 15.0 µg/m³ | 92.0 µg/m³ |
| =16 | Lubumbashi | Democratic Republic of Congo | 81 | 25.3 µg/m³ | 91.0 µg/m³ |
| =16 | Indore | India | 150 | 55.2 µg/m³ | 91.0 µg/m³ |
| =16 | Nowrangapur | India | 89 | 29.6 µg/m³ | 91.0 µg/m³ |
| 17 | Guayaquil | Ecuador | 43 | 7.7 µg/m³ | 89.0 µg/m³ |
| 18 | Iztapalapa | Mexico | 21 | 3.7 µg/m³ | 88.0 µg/m³ |
| 19 | Chicago | United States | 61 | 14.6 µg/m³ | 87.0 µg/m³ |
| =20 | Medellín | Colombia | 42 | 7.6 µg/m³ | 86.0 µg/m³ |
| =20 | León de los Aldama | Mexico | 7 | 1.3 µg/m³ | 86.0 µg/m³ |
| =20 | Abu Dhabi | United Arab Emirates | 91 | 30.7 µg/m³ | 86.0 µg/m³ |
| =21 | Puebla | Mexico | 8 | 1.4 µg/m³ | 85.0 µg/m³ |
| =21 | Kyoto | Japan | 49 | 8.8 µg/m³ | 85.0 µg/m³ |
| =22 | Nagoya | Japan | 44 | 8.0 µg/m³ | 84.0 µg/m³ |
| =22 | Ciudad Juárez | Mexico | 39 | 7.1 µg/m³ | 84.0 µg/m³ |
| =22 | San Diego | United States | 65 | 16.7 µg/m³ | 84.0 µg/m³ |
| =23 | Mexico City | Mexico | 23 | 4.2 µg/m³ | 83.0 µg/m³ |
| =23 | Casablanca | Morocco | 35 | 6.3 µg/m³ | 83.0 µg/m³ |
| =23 | Doha | Qatar | 125 | 45.1 µg/m³ | 83.0 µg/m³ |
| =23 | Ecatepec de Morelos | Mexico | 23 | 4.2 µg/m³ | 83.0 µg/m³ |
| =23 | Taizhou | China | 61 | 14.4 µg/m³ | 83.0 µg/m³ |
| =24 | Shantou | China | 53 | 10.1 µg/m³ | 82.0 µg/m³ |
| =24 | Córdoba | Argentina | 43 | 7.7 µg/m³ | 82.0 µg/m³ |
| =25 | Tijuana | Mexico | 67 | 17.8 µg/m³ | 80.0 µg/m³ |
| =25 | Camayenne | Guinea | 36 | 6.5 µg/m³ | 80.0 µg/m³ |
| =25 | Conakry | Guinea | 36 | 6.5 µg/m³ | 80.0 µg/m³ |
| =25 | Santiago de Querétaro | Mexico | 7 | 1.3 µg/m³ | 80.0 µg/m³ |
| =26 | Ningbo | China | 64 | 16.1 µg/m³ | 79.0 µg/m³ |
| =26 | Sana'a | Yemen | 59 | 13.6 µg/m³ | 79.0 µg/m³ |
| =26 | Baku | Azerbaijan | 52 | 9.6 µg/m³ | 79.0 µg/m³ |
| =26 | Sanaa | Yemen | 59 | 13.6 µg/m³ | 79.0 µg/m³ |
| =27 | Rio de Janeiro | Brazil | 65 | 16.5 µg/m³ | 78.0 µg/m³ |
| =27 | Kolkata | India | 175 | 90.3 µg/m³ | 78.0 µg/m³ |
| =27 | Wenzhou | China | 69 | 18.7 µg/m³ | 78.0 µg/m³ |
| =27 | Cali | Colombia | 20 | 3.6 µg/m³ | 78.0 µg/m³ |
| =27 | Almaty | Kazakhstan | 56 | 11.7 µg/m³ | 78.0 µg/m³ |
| =27 | Phoenix | United States | 38 | 6.8 µg/m³ | 78.0 µg/m³ |
| =27 | Kobe | Japan | 54 | 10.6 µg/m³ | 78.0 µg/m³ |
| =28 | Algiers | Algeria | 37 | 6.7 µg/m³ | 77.0 µg/m³ |
| =28 | Durban | South Africa | 54 | 10.9 µg/m³ | 77.0 µg/m³ |
| =29 | Pune | India | 105 | 37.1 µg/m³ | 76.0 µg/m³ |
| =29 | Philadelphia | United States | 27 | 4.8 µg/m³ | 76.0 µg/m³ |
| =30 | Brasilia | Brazil | 17 | 3.0 µg/m³ | 75.0 µg/m³ |
| =30 | Qujing | China | 29 | 5.3 µg/m³ | 75.0 µg/m³ |
| 31 | Khulna | Bangladesh | 170 | 82.9 µg/m³ | 73.0 µg/m³ |
| =32 | Queens | United States | 20 | 3.6 µg/m³ | 71.0 µg/m³ |
| =32 | Bhopāl | India | 71 | 19.7 µg/m³ | 71.0 µg/m³ |
| =32 | Barquisimeto | Venezuela | 33 | 6.0 µg/m³ | 71.0 µg/m³ |
| =33 | Dhaka | Bangladesh | 165 | 75.9 µg/m³ | 70.0 µg/m³ |
| =33 | New York City | United States | 27 | 4.8 µg/m³ | 70.0 µg/m³ |
| =33 | Brooklyn | United States | 27 | 4.8 µg/m³ | 70.0 µg/m³ |
| =33 | Manhattan | United States | 27 | 4.8 µg/m³ | 70.0 µg/m³ |
| =33 | Jamshedpur | India | 186 | 105.2 µg/m³ | 70.0 µg/m³ |
| =33 | Qinzhou | China | 52 | 9.4 µg/m³ | 70.0 µg/m³ |
| =34 | Alexandria | Egypt | 51 | 9.2 µg/m³ | 69.0 µg/m³ |
| =34 | Osaka | Japan | 55 | 11.1 µg/m³ | 69.0 µg/m³ |
| =34 | Vadodara | India | 117 | 42.1 µg/m³ | 69.0 µg/m³ |
| =34 | The Bronx | United States | 26 | 4.7 µg/m³ | 69.0 µg/m³ |
| =34 | Nashik | India | 134 | 48.8 µg/m³ | 69.0 µg/m³ |
| =35 | Sapporo | Japan | 23 | 4.2 µg/m³ | 68.0 µg/m³ |
| =35 | Yangjiang | China | 58 | 13.0 µg/m³ | 68.0 µg/m³ |
| =36 | Kabul | Afghanistan | 59 | 13.3 µg/m³ | 67.0 µg/m³ |
| =36 | Navi Mumbai | India | 163 | 72.9 µg/m³ | 67.0 µg/m³ |
| =36 | Zhuhai | China | 54 | 10.7 µg/m³ | 67.0 µg/m³ |
| =36 | Quito | Ecuador | 38 | 6.8 µg/m³ | 67.0 µg/m³ |
| =36 | Munich | Germany | 12 | 2.2 µg/m³ | 67.0 µg/m³ |
| =37 | Guatemala City | Guatemala | 19 | 3.4 µg/m³ | 66.0 µg/m³ |
| =37 | Paris | France | 28 | 5.1 µg/m³ | 66.0 µg/m³ |
| =38 | Riyadh | Saudi Arabia | 403 | 328.8 µg/m³ | 65.0 µg/m³ |
| =38 | Nanning | China | 59 | 13.2 µg/m³ | 65.0 µg/m³ |
| =38 | Kaduna | Nigeria | 175 | 89.2 µg/m³ | 65.0 µg/m³ |
| =38 | Dazhou | China | 79 | 24.2 µg/m³ | 65.0 µg/m³ |
| =38 | Belém | Brazil | 52 | 9.8 µg/m³ | 65.0 µg/m³ |
| =38 | Rājkot | India | 81 | 25.4 µg/m³ | 65.0 µg/m³ |
| =39 | Lima | Peru | 65 | 16.4 µg/m³ | 64.0 µg/m³ |
| =39 | Santiago | Chile | 51 | 9.3 µg/m³ | 64.0 µg/m³ |
| =39 | Los Angeles | United States | 65 | 16.4 µg/m³ | 64.0 µg/m³ |
| =39 | Toronto | Canada | 43 | 7.8 µg/m³ | 64.0 µg/m³ |
| =39 | Ganzhou | China | 78 | 23.7 µg/m³ | 64.0 µg/m³ |
| =39 | Curitiba | Brazil | 54 | 10.7 µg/m³ | 64.0 µg/m³ |
| =39 | Maoming | China | 88 | 29.2 µg/m³ | 64.0 µg/m³ |
| =39 | Callao | Peru | 65 | 16.4 µg/m³ | 64.0 µg/m³ |
| =39 | Shubrā al Khaymah | Egypt | 54 | 10.6 µg/m³ | 64.0 µg/m³ |
Methodology: Current pollutant concentrations are sampled from WeatherAPI for up to 400 large cities; US AQI values are calculated from PM2.5 using EPA breakpoints.
Why Is Ground-Level Ozone So High in These Cities?
Ground-level ozone forms when sunlight drives reactions between pollutants from traffic, industry and other sources. Concentrations often peak on warm, sunny afternoons and can irritate the lungs even when particle pollution is modest.
Frequently Asked Questions: Cities With the Highest Ozone Right Now
Which city has the highest ozone right now?
Among the major cities we track, Houston has the highest current ozone concentration at about 154.0 µg/m³ (as of October 21, 2026).
Is ground-level ozone the same as the ozone layer?
It is the same molecule but in the wrong place: stratospheric ozone protects Earth, while ozone near the ground is a harmful air pollutant.