SmogRank / History / City race
Cities in South Africa, worst air first, day by day
Each measured city's average over the 30 days to every day since January 2023, worst first. Find your own city to follow it through the race, or keep to one country.
The worst cities in South Africa for PM2.5 over the 30 days to 19 Feb 2024: Bloemfontein 22.2 µg/m³, Johannesburg 19.7 µg/m³ and Vereeniging 16.5 µg/m³.
- 1BloemfonteinFree State22.2
- 2JohannesburgGauteng19.7
- 3VereenigingGauteng16.5
- 4ThembisaGauteng15.8
- 5BrakpanGauteng14.4
- 6MiddelburgMpumalanga13.9
- 7HartbeespoortNorth West13.5
- 8Richards BayKwaZulu-Natal8.8
- 9KlerksdorpNorth West6.5
- 10LichtenburgNorth West3.3
Not counted on this day, too few days measured: Kuils River since 17 Feb 2024, Secunda since 12 Feb 2024, Brits since 12 Feb 2024 and 2 more cities. Days missing from the source archive fall in this window, so fewer countries are counted.
Cities counted each day
A city's number is its average over the 30 days, shown only when 21 of them were measured (5 of 7 on the 7-day race), the same minimum as the 30- and 7-day boards. A city whose monitors go quiet fades out where it stood rather than sliding down, so a gap never reads as cleaner air. 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.