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 2 Jul 2026: Chile 46.6 µg/m³, Pakistan 30.2 µg/m³ and India 28.3 µg/m³.
- 1Chile46 cities46.6
- 2Pakistan13 cities30.2
- 3India213 cities28.3
- 4Malawi5 cities26.8
- 5Peru6 cities25.5
- 6Lebanon3 cities17.2
- 7Brazil6 cities14.8
- 8New Zealand6 cities14.7
- 9South Korea136 cities12.1
- 10Mexico46 cities12.1
- 11Slovakia36 cities12.0
- 12Malta3 cities11.8
- 13Senegal3 cities11.4
- 14Kazakhstan4 cities11.3
- 15Bosnia and Herzegovina3 cities11.0
- 16Serbia8 cities10.8
- 17Italy11 cities10.6
- 18Thailand76 cities10.2
- 19Poland54 cities9.6
- 20Romania20 cities9.6
+ 20 more countries, 9.3 µg/m³ and below
- 30United States857 cities6.8
Not counted on this day, too few cities measured: Ireland since 27 Jun 2026, Belgium since 14 Jun 2026, Greece since 14 Jun 2026 and 8 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.