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 30 Sep 2026: Pakistan 57.6 µg/m³, Malawi 53.1 µg/m³ and Indonesia 47.8 µg/m³.
- 1Pakistan15 cities57.6
- 2Malawi4 cities53.1
- 3Indonesia4 cities47.8
- 4Philippines3 cities29.5
- 5India223 cities27.2
- 6Chile47 cities20.3
- 7Serbia8 cities17.8
- 8Ghana5 cities16.5
- 9Kazakhstan5 cities16.0
- 10South Africa38 cities14.9
- 11Taiwan44 cities14.2
- 12Poland60 cities12.3
- 13South Korea139 cities12.2
- 14Bosnia and Herzegovina5 cities12.1
- 15Hong Kong12 cities12.0
- 16Senegal4 cities10.3
- 17Switzerland10 cities, was 1110.1
- 18Italy32 cities10.1
- 19Mexico45 cities9.8
- 20The Netherlands42 cities9.6
+ 32 more countries, 9.6 µg/m³ and below
- 45United States900 cities5.2
Not counted on this day, too few cities measured: Nigeria since 20 Sep 2026, Nepal since 14 Sep 2026, Kyrgyzstan since 11 Sep 2026 and Lithuania since 12 Aug 2026.
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.