SmogRank / History / Country race
Countries, worst air first, day by day
Each country's typical measured city over the 30 days to every day since January 2023, worst first. Press Play to watch the order change, or drag the slider to any day.
The worst countries for PM2.5 over the 30 days to 16 Jul 2026: Chile 49.1 µg/m³, Pakistan 31.8 µg/m³ and Malawi 31.3 µg/m³.
- 1Chile46 cities49.1
- 2Pakistan13 cities31.8
- 3Malawi5 cities31.3
- 4Peru6 cities26.1
- 5India212 cities24.1
- 6Lebanon3 cities18.9
- 7New Zealand6 cities14.9
- 8Mexico44 cities13.4
- 9Kazakhstan4 cities13.1
- 10Brazil6 cities12.4
- 11Italy32 cities12.1
- 12Martinique3 cities12.1
- 13Slovakia39 cities11.8
- 14Spain25 cities11.6
- 15Malta5 cities11.5
- 16Serbia8 cities11.5
- 17Bosnia and Herzegovina4 cities11.4
- 18South Korea131 cities11.1
- 19Montenegro4 cities9.9
- 20Romania25 cities9.7
+ 25 more countries, 9.3 µg/m³ and below
- 27United States864 cities8.5
Not counted on this day, too few cities measured: Thailand since 11 Jul 2026, Norway since 6 Jul 2026, Greece since 14 Jun 2026 and 3 more countries.
Countries counted each day
A country's number is its typical measured city: the median of its cities' means over the 30 days (a city needs 21 of them measured; 5 of 7 on the 7-day race), shown only with 3 such cities. A country whose monitors go quiet fades out where it stood rather than sliding down, so a gap never reads as cleaner air; "was" beside a city count marks a month after many cities joined or left. Some large countries are thin or missing because their monitors' licences don't allow reuse. How we rank.
Not covered: the government monitoring networks of China and Turkey, which publish only on their own websites; we are building the readers for them. Most cities there are missing from this board, not clean. Why.