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 14 May 2026: Pakistan 63.4 µg/m³, Chile 34.7 µg/m³ and India 33.1 µg/m³.
- 1Pakistan15 cities63.4
- 2Chile45 cities34.7
- 3India229 cities33.1
- 4Lebanon3 cities21.8
- 5Peru6 cities21.4
- 6Thailand79 cities18.3
- 7Mexico42 cities17.8
- 8Malta5 cities16.7
- 9Kazakhstan4 cities16.0
- 10Malawi5 cities14.3
- 11Hong Kong13 cities14.0
- 12Laos3 cities13.9
- 13Serbia8 cities12.3
- 14Taiwan44 cities12.0
- 15South Korea131 cities11.4
- 16Greece10 cities10.6
- 17North Macedonia14 cities10.1
- 18Italy36 cities8.8
- 19Brazil6 cities8.6
- 20New Zealand6 cities8.4
+ 27 more countries, 8.3 µg/m³ and below
- 34United States846 cities5.4
Not counted on this day, too few cities measured: Czechia since 14 May 2026, Slovenia since 12 May 2026, Senegal since 10 May 2026 and 5 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.