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 14 Apr 2026: Laos 91.2 µg/m³, Kazakhstan 40.0 µg/m³ and Pakistan 37.5 µg/m³.
- 1Laos3 cities91.2
- 2Kazakhstan4 cities40.0
- 3Pakistan12 cities37.5
- 4India241 cities34.7
- 5Thailand84 cities31.1
- 6South Korea141 cities25.0
- 7Peru6 cities23.6
- 8Chile47 cities23.2
- 9Ghana3 cities19.1
- 10Serbia4 cities18.9
- 11Taiwan44 cities17.8
- 12Poland59 cities17.7
- 13Mexico54 cities17.0
- 14Hong Kong13 cities14.7
- 15North Macedonia14 cities14.5
- 16Romania29 cities13.9
- 17Malta5 cities13.7
- 18Slovakia42 cities13.0
- 19Latvia4 cities12.7
- 20Hungary13 cities12.3
+ 27 more countries, 11.3 µg/m³ and below
- 41United States872 cities6.7
Not counted on this day, too few cities measured: Bosnia and Herzegovina since 13 Apr 2026, Philippines since 8 Apr 2026, Kyrgyzstan since 5 Apr 2026 and Spain since 18 Feb 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.