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Air in Ekurhuleni

Air in 2025 (modelled): nitrogen dioxide near the ground averaged 38 µg/m³, 3.8 times WHO’s guideline of 10; winters 48 µg/m³, summers 28 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 202530 µg/m³46 µg/m³137 µmol/m²153 µmol/m²
November 202530 µg/m³44 µg/m³148 µmol/m²137 µmol/m²
October 202535 µg/m³51 µg/m³168 µmol/m²176 µmol/m²
September 202536 µg/m³48 µg/m³168 µmol/m²187 µmol/m²
August 202552 µg/m³40 µg/m³183 µmol/m²191 µmol/m²
July 202552 µg/m³31 µg/m³205 µmol/m²224 µmol/m²
June 202547 µg/m³29 µg/m³217 µmol/m²214 µmol/m²
May 202549 µg/m³31 µg/m³247 µmol/m²255 µmol/m²
April 202536 µg/m³30 µg/m³173 µmol/m²162 µmol/m²
March 202536 µg/m³42 µg/m³164 µmol/m²176 µmol/m²
February 202527 µg/m³38 µg/m³165 µmol/m²202 µmol/m²
January 202529 µg/m³42 µg/m³137 µmol/m²159 µmol/m²
December 202427 µg/m³46 µg/m³131 µmol/m²143 µmol/m²
November 202433 µg/m³54 µg/m³148 µmol/m²157 µmol/m²
October 202433 µg/m³60 µg/m³173 µmol/m²218 µmol/m²
September 202435 µg/m³52 µg/m³156 µmol/m²173 µmol/m²
August 202445 µg/m³43 µg/m³176 µmol/m²182 µmol/m²
July 202450 µg/m³32 µg/m³183 µmol/m²150 µmol/m²
June 202450 µg/m³27 µg/m³245 µmol/m²251 µmol/m²
May 202455 µg/m³31 µg/m³218 µmol/m²249 µmol/m²
April 202435 µg/m³31 µg/m³166 µmol/m²177 µmol/m²
March 202433 µg/m³38 µg/m³173 µmol/m²211 µmol/m²
February 202431 µg/m³43 µg/m³144 µmol/m²181 µmol/m²
January 202431 µg/m³50 µg/m³129 µmol/m²167 µmol/m²

Over the last five years the NO2 column averaged 205 µmol/m² in winter against 145 µmol/m² in summer, and the SO2 column 209 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: 26 µg/m³2005: 28 µg/m³2006: 28 µg/m³2007: 29 µg/m³2008: 31 µg/m³2009: 30 µg/m³2010: 31 µg/m³2011: 31 µg/m³2012: 32 µg/m³2013: 32 µg/m³2014: 33 µg/m³2015: 34 µg/m³2016: 34 µg/m³2017: 34 µg/m³2018: 34 µg/m³2019: 38 µg/m³2020: 36 µg/m³2021: 35 µg/m³2022: 37 µg/m³2023: 37 µg/m³2024: 38 µg/m³2025: 38 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
200426 µg/m³
200528 µg/m³
200628 µg/m³
200729 µg/m³
200831 µg/m³
200930 µg/m³
201031 µg/m³
201131 µg/m³
201232 µg/m³
201332 µg/m³
201433 µg/m³
201534 µg/m³
201634 µg/m³
201734 µg/m³
201834 µg/m³
201938 µg/m³
202036 µg/m³
202135 µg/m³
202237 µg/m³
202337 µg/m³
202438 µg/m³
202538 µg/m³

Every municipality, ranked · Everything we hold for Ekurhuleni · 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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