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 20 Aug 2026: Malawi 35.9 µg/m³, Pakistan 34.6 µg/m³ and Chile 30.9 µg/m³.
- 1Malawi5 cities35.9
- 2Pakistan13 cities34.6
- 3Chile47 cities30.9
- 4Lebanon3 cities22.1
- 5Nepal3 cities21.3
- 6India214 cities21.2
- 7Mexico48 cities15.5
- 8Italy32 cities14.0
- 9New Zealand6 cities13.5
- 10Martinique3 cities12.6
- 11Kazakhstan4 cities12.2
- 12Brazil6 cities12.1
- 13Hong Kong3 cities11.7
- 14Slovakia41 cities11.3
- 15North Macedonia14 cities, was 410.8
- 16Serbia8 cities10.6
- 17Taiwan44 cities10.6
- 18Montenegro4 cities10.3
- 19South Korea127 cities10.2
- 20Thailand65 cities10.0
+ 27 more countries, 9.9 µg/m³ and below
- 29United States856 cities8.6
Not counted on this day, too few cities measured: Bosnia and Herzegovina since 16 Aug 2026, Malta since 12 Aug 2026, Peru since 17 Jul 2026 and Norway since 6 Jul 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.