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 5 Aug 2026: Malawi 37.5 µg/m³, Pakistan 36.7 µg/m³ and Chile 26.4 µg/m³.
- 1Malawi5 cities37.5
- 2Pakistan14 cities36.7
- 3Chile47 cities26.4
- 4Nepal3 cities23.3
- 5India214 cities21.0
- 6Lebanon3 cities20.4
- 7Mexico46 cities16.7
- 8Slovakia39 cities16.1
- 9Malta6 cities15.5
- 10Italy30 cities15.3
- 11Brazil6 cities15.1
- 12Kazakhstan4 cities13.9
- 13South Korea128 cities13.3
- 14Switzerland11 cities, was 313.2
- 15New Zealand6 cities12.3
- 16Poland59 cities, was 1412.3
- 17Hungary13 cities, was 411.8
- 18Bosnia and Herzegovina5 cities11.6
- 19Japan562 cities11.2
- 20Romania21 cities, was 711.1
+ 30 more countries, 10.3 µg/m³ and below
- 28United States852 cities9.2
Not counted on this day, too few cities measured: Ghana since 20 Jul 2026, Philippines since 19 Jul 2026, Peru since 10 Jul 2026 and Norway since 4 Jul 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.