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 21 Jul 2026: Chile 46.2 µg/m³, Malawi 33.9 µg/m³ and Pakistan 32.0 µg/m³.
- 1Chile45 cities46.2
- 2Malawi5 cities33.9
- 3Pakistan13 cities32.0
- 4India203 cities23.2
- 5Lebanon3 cities20.9
- 6New Zealand6 cities17.3
- 7Mexico47 cities14.3
- 8Malta5 cities13.4
- 9Kazakhstan4 cities13.0
- 10Brazil6 cities12.7
- 11Martinique3 cities12.5
- 12Italy31 cities12.3
- 13Serbia8 cities11.8
- 14Bosnia and Herzegovina5 cities11.5
- 15Spain21 cities11.4
- 16South Korea132 cities11.4
- 17Slovakia39 cities11.2
- 18Montenegro4 cities10.6
- 19North Macedonia11 cities10.2
- 20Romania24 cities10.2
+ 24 more countries, 10.0 µg/m³ and below
- 22United States863 cities9.7
Not counted on this day, too few cities measured: Latvia since 21 Jul 2026, Peru since 17 Jul 2026, Thailand since 11 Jul 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.