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 17 Jan 2026: Pakistan 219.0 µg/m³, Kyrgyzstan 102.7 µg/m³ and Bosnia and Herzegovina 73.1 µg/m³.
- 1Pakistan12 cities219.0
- 2Kyrgyzstan3 cities102.7
- 3Bosnia and Herzegovina5 cities73.1
- 4Kazakhstan4 cities63.8
- 5Montenegro4 cities58.0
- 6North Macedonia10 cities52.0
- 7Thailand78 cities41.7
- 8Ghana4 cities40.7
- 9Romania23 cities34.9
- 10Hungary12 cities34.4
- 11Poland58 cities33.2
- 12Hong Kong13 cities29.9
- 13Slovenia12 cities27.0
- 14Latvia4 cities26.2
- 15South Korea140 cities25.8
- 16Philippines3 cities23.5
- 17Bulgaria4 cities22.7
- 18Austria42 cities21.5
- 19Taiwan44 cities21.2
- 20Laos3 cities21.0
+ 23 more countries, 17.4 µg/m³ and below
- 40United States883 cities, was 2655.6
Not counted on this day, too few cities measured: France since 17 Jan 2026, India since 13 Jan 2026, Senegal since 10 Jan 2026 and 7 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.