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 9 Mar 2026: Pakistan 104.5 µg/m³, Kazakhstan 56.1 µg/m³ and India 47.6 µg/m³.
- 1Pakistan13 cities104.5
- 2Kazakhstan4 cities56.1
- 3India218 cities47.6
- 4Laos3 cities32.7
- 5Ghana3 cities31.2
- 6Thailand84 cities28.8
- 7North Macedonia13 cities26.4
- 8Poland58 cities26.0
- 9Romania28 cities23.8
- 10Latvia4 cities22.8
- 11Montenegro5 cities22.7
- 12Bosnia and Herzegovina6 cities22.4
- 13Hungary13 cities21.5
- 14South Korea140 cities20.6
- 15Mexico44 cities20.1
- 16Senegal3 cities19.9
- 17Hong Kong13 cities19.5
- 18Slovenia12 cities17.5
- 19Chile43 cities17.4
- 20Bulgaria7 cities16.6
+ 27 more countries, 16.5 µg/m³ and below
- 37United States877 cities7.4
Not counted on this day, too few cities measured: Kyrgyzstan since 28 Feb 2026, Spain since 18 Feb 2026 and Slovakia since 9 Jan 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.