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 7 days to 3 Sep 2026: Malawi 68.4 µg/m³, Indonesia 42.7 µg/m³ and Pakistan 35.4 µg/m³.
- 1Malawi3 cities68.4
- 2Indonesia4 cities42.7
- 3Pakistan15 cities35.4
- 4Chile46 cities23.6
- 5South Africa44 cities21.3
- 6Lebanon3 cities20.3
- 7India169 cities, was 21220.1
- 8Montenegro4 cities18.2
- 9Ghana5 cities17.4
- 10Nepal3 cities17.4
- 11Kyrgyzstan3 cities16.5
- 12Mexico48 cities15.7
- 13North Macedonia15 cities14.8
- 14Greece8 cities14.5
- 15Serbia8 cities13.4
- 16Kazakhstan5 cities13.1
- 17Italy32 cities12.5
- 18Thailand75 cities11.0
- 19Hong Kong12 cities10.3
- 20Romania26 cities10.1
+ 29 more countries, 9.6 µg/m³ and below
- 25United States892 cities7.3
Not counted on this day, too few cities measured: Latvia since 3 Sep 2026, Martinique since 2 Sep 2026, Bosnia and Herzegovina since 12 Aug 2026 and 4 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.