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Air in Sedibeng

Air in 2025 (modelled): nitrogen dioxide near the ground averaged 36 µg/m³, 3.6 times WHO’s guideline of 10; winters 44 µg/m³, summers 27 µg/m³.

Nitrogen dioxide (NO2) comes mostly from burning: power stations, vehicles, industry. Near the ground is what people breathe. The column is all of it in the air above, from the ground to the top of the sky, which is what a satellite sees. Sulphur dioxide (SO2) comes mostly from burning coal. Ozone forms in sunlight from other pollutants.

Modelled, not measured: these figures come from the Copernicus Atmosphere Monitoring Service’s reanalysis, a weather and chemistry model that takes in satellite readings. Its cells are about 80 km across, so a busy road or a smoky winter evening in one suburb is smoothed into the region around it. It is not a reading at any address.

2025

WHO’s 2021 guideline for nitrogen dioxide is 10 µg/m³ as a yearly mean. It is a long-term health guideline, not a legal limit (South Africa’s national standard for the yearly mean is set separately), and these are modelled regional means, not readings where you live.

Month by month

MonthNO2 near the groundOzone near the groundNO2 columnSO2 column
December 202529 µg/m³48 µg/m³134 µmol/m²157 µmol/m²
November 202528 µg/m³46 µg/m³144 µmol/m²143 µmol/m²
October 202533 µg/m³52 µg/m³160 µmol/m²175 µmol/m²
September 202535 µg/m³49 µg/m³162 µmol/m²195 µmol/m²
August 202548 µg/m³41 µg/m³180 µmol/m²202 µmol/m²
July 202548 µg/m³31 µg/m³201 µmol/m²236 µmol/m²
June 202544 µg/m³30 µg/m³207 µmol/m²217 µmol/m²
May 202545 µg/m³32 µg/m³230 µmol/m²250 µmol/m²
April 202535 µg/m³30 µg/m³165 µmol/m²166 µmol/m²
March 202535 µg/m³44 µg/m³159 µmol/m²180 µmol/m²
February 202526 µg/m³42 µg/m³159 µmol/m²196 µmol/m²
January 202528 µg/m³45 µg/m³135 µmol/m²160 µmol/m²
December 202425 µg/m³51 µg/m³128 µmol/m²152 µmol/m²
November 202431 µg/m³57 µg/m³145 µmol/m²165 µmol/m²
October 202431 µg/m³62 µg/m³164 µmol/m²216 µmol/m²
September 202433 µg/m³53 µg/m³152 µmol/m²183 µmol/m²
August 202441 µg/m³43 µg/m³169 µmol/m²189 µmol/m²
July 202446 µg/m³32 µg/m³175 µmol/m²160 µmol/m²
June 202447 µg/m³29 µg/m³233 µmol/m²250 µmol/m²
May 202452 µg/m³33 µg/m³209 µmol/m²253 µmol/m²
April 202433 µg/m³33 µg/m³163 µmol/m²188 µmol/m²
March 202433 µg/m³42 µg/m³172 µmol/m²215 µmol/m²
February 202429 µg/m³45 µg/m³138 µmol/m²181 µmol/m²
January 202428 µg/m³52 µg/m³123 µmol/m²166 µmol/m²

Over the last five years the NO2 column averaged 199 µmol/m² in winter against 140 µmol/m² in summer, and the SO2 column 217 µmol/m² against 169 µmol/m²: still winter air holds what is burnt close to the ground, and more is burnt to keep warm.

Every year since 2003

2003: 26 µg/m³2004: 25 µg/m³2005: 26 µg/m³2006: 26 µg/m³2007: 27 µg/m³2008: 30 µg/m³2009: 29 µg/m³2010: 29 µg/m³2011: 29 µg/m³2012: 30 µg/m³2013: 30 µg/m³2014: 31 µg/m³2015: 32 µg/m³2016: 32 µg/m³2017: 32 µg/m³2018: 33 µg/m³2019: 35 µg/m³2020: 34 µg/m³2021: 33 µg/m³2022: 35 µg/m³2023: 35 µg/m³2024: 36 µg/m³2025: 36 µg/m³200320082013201820232025
Nitrogen dioxide near the ground, each year’s mean (modelled). The line is WHO’s yearly guideline, 10 µg/m³.
Show the numbers
Nitrogen dioxide near the ground, the mean of each year, 2003 to 2025: every figure
When or whatFigure
200326 µg/m³
200425 µg/m³
200526 µg/m³
200626 µg/m³
200727 µg/m³
200830 µg/m³
200929 µg/m³
201029 µg/m³
201129 µg/m³
201230 µg/m³
201330 µg/m³
201431 µg/m³
201532 µg/m³
201632 µg/m³
201732 µg/m³
201833 µg/m³
201935 µg/m³
202034 µg/m³
202133 µg/m³
202235 µg/m³
202335 µg/m³
202436 µg/m³
202536 µg/m³

Every municipality, ranked · Everything we hold for Sedibeng · On the explore map

Source

Modelled, not measured: these figures come from the Copernicus Atmosphere Monitoring Service’s reanalysis, a weather and chemistry model that takes in satellite readings. Its cells are about 80 km across, so a busy road or a smoky winter evening in one suburb is smoothed into the region around it. It is not a reading at any address.

How we worked this out

What we changed: we averaged the reanalysis’s monthly means over each place by its area in each 0.75 degree cell, turned NO2 and ozone on the model’s lowest level from mass mixing ratio into micrograms per m3 with the month’s air density (surface pressure and temperature), and the columns from kg per m2 into micromol per m2.

Particles (PM2.5, PM10) and sulphur dioxide near the ground are not shown yet: the model reads them far higher over Gauteng and the Highveld than is plausible for a regional mean, so they wait for a check against ground stations.

Contains modified Copernicus Atmosphere Monitoring Service information 2003 to 2025. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains. Copernicus Atmosphere Monitoring Service (2020): CAMS global reanalysis (EAC4) monthly averaged fields. Copernicus Atmosphere Monitoring Service (CAMS) Atmosphere Data Store, DOI 10.24381/fd75fff2. Inness, A. and others (2019): The CAMS reanalysis of atmospheric composition, Atmos. Chem. Phys., 19, 3515 to 3556. Under CC BY 4.0.

Dataset: air quality by municipality, release of 12 November 2026.

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