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 21 Feb 2026: Pakistan 110.8 µg/m³, India 94.9 µg/m³ and Kazakhstan 71.3 µg/m³.
- 1Pakistan12 cities110.8
- 2India3 cities, was 23994.9
- 3Kazakhstan4 cities71.3
- 4Thailand85 cities30.2
- 5Senegal3 cities29.3
- 6Latvia4 cities28.9
- 7Poland56 cities28.2
- 8Ghana3 cities27.8
- 9Laos3 cities27.7
- 10Mexico45 cities23.2
- 11Hong Kong13 cities21.9
- 12South Korea140 cities21.2
- 13Taiwan44 cities19.9
- 14Philippines3 cities17.2
- 15Chile45 cities17.0
- 16Hungary13 cities16.8
- 17Romania29 cities16.8
- 18North Macedonia6 cities16.4
- 19Peru6 cities14.9
- 20Bosnia and Herzegovina6 cities14.0
+ 26 more countries, 13.2 µg/m³ and below
- 38United States863 cities6.9
Not counted on this day, too few cities measured: Czechia since 19 Feb 2026, Kyrgyzstan since 19 Feb 2026, Malawi since 18 Feb 2026 and 3 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.