SmogRank / World / Africa / South Africa / Free State

Most polluted cities in Free State, South Africa

1 measured city, last 7 days; 1 above the WHO 24-hour guideline. Worst: Sasolburg at 19.7 µg/m³, #195 in the world.

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

Estimated: cities without a monitor

Free State cities we can't measure, with model estimates for the last 7 days. Listed by population, not ranked: estimates aren't precise enough to rank. Model estimates from the Copernicus Atmosphere Monitoring Service (CAMS), adjusted to measured cities nearby where there are any. Adjusted, a single day lands within ×1.5 of what a monitor would read about two times in three; unadjusted, it can be off by half or double. Treat them as a guide, not a measurement.

City	7-day estimate	Band
Bloemfontein	≈ 8 µg/m³	Good
Welkom	≈ 12 µg/m³	Moderate
Botshabelo	≈ 8 µg/m³	Good
Virginia	≈ 12 µg/m³	Moderate
Kroonstad	≈ 12 µg/m³	Moderate
Kutloanong	≈ 12 µg/m³	Moderate
Bethlehem	≈ 10 µg/m³	Moderate
Phuthaditjhaba	≈ 10 µg/m³	Moderate
Odendaalsrus	≈ 12 µg/m³	Moderate
Thaba Nchu	≈ 8 µg/m³	Good
Bothaville	≈ 12 µg/m³	Moderate
Parys	≈ 15 µg/m³	Moderate
Viljoenskroon	≈ 12 µg/m³	Moderate
Ficksburg	≈ 12 µg/m³	Moderate
Wesselsbron	≈ 11 µg/m³	Moderate
Senekal	≈ 11 µg/m³	Moderate
Theunissen	≈ 10 µg/m³	Moderate
Harrismith	≈ 11 µg/m³	Moderate
Heilbron	≈ 14 µg/m³	Moderate
Allanridge	≈ 12 µg/m³	Moderate
Frankfort	≈ 15 µg/m³	Moderate
Ladybrand	≈ 11 µg/m³	Moderate
Bultfontein	≈ 9 µg/m³	Good
Phomolong	≈ 12 µg/m³	Moderate
Reitz	≈ 11 µg/m³	Moderate
Deneysville	≈ 17 µg/m³	Moderate
Hennenman	≈ 12 µg/m³	Moderate
Vrede	≈ 11 µg/m³	Moderate
Hlohlolwane	≈ 11 µg/m³	Moderate
Villiers	≈ 13 µg/m³	Moderate
Hoopstad	≈ 11 µg/m³	Moderate
Zastron	≈ 7 µg/m³	Good
Marquard	≈ 11 µg/m³	Moderate
Tshiame	≈ 10 µg/m³	Moderate
Vredefort	≈ 12 µg/m³	Moderate
Winburg	≈ 10 µg/m³	Moderate
Koppies	≈ 13 µg/m³	Moderate
Fouriesburg	≈ 10 µg/m³	Moderate
Winnie Mandela	≈ 8 µg/m³	Good
Mamafubedu	≈ 12 µg/m³	Moderate

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SmogRank, most polluted cities in Free State, South Africa, PM2.5, last 7 days to 2 Oct 2026, 08:00 UTC, smogrank.com/za/region/free-state?w=7d.

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Updated 2026-10-02 08:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index.