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 29 Mar 2023: North Macedonia 25.9 µg/m³, Slovenia 19.6 µg/m³ and Romania 19.4 µg/m³.
- 1North Macedonia9 cities25.9
- 2Slovenia8 cities19.6
- 3Romania7 cities19.4
- 4Poland70 cities19.3
- 5Kosovo4 cities16.8
- 6Czechia36 cities15.0
- 7Slovakia30 cities14.9
- 8Greece9 cities14.8
- 9Bosnia and Herzegovina3 cities13.0
- 10Austria17 cities12.0
- 11Italy27 cities, was 611.8
- 12France119 cities10.9
- 13Latvia4 cities9.7
- 14Belgium34 cities8.8
- 15Germany170 cities8.5
- 16Spain83 cities8.1
- 17Portugal8 cities7.8
- 18The Netherlands25 cities7.4
- 19Norway17 cities7.2
- 20United States417 cities7.0
+ 2 more countries, 4.7 µg/m³ and below
Not counted on this day, too few cities measured: Croatia since 24 Mar 2023, Reunion since 19 Mar 2023, Lithuania since 15 Mar 2023 and 15 more countries. Days missing from the source archive fall in this window, so fewer countries are counted.
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.