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Air in The Msunduzi

Air in 2025 (modelled): nitrogen dioxide near the ground averaged 14 µg/m³, 1.4 times WHO’s guideline of 10; winters 22 µg/m³, summers 9.2 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 20258.9 µg/m³50 µg/m³61 µmol/m²48 µmol/m²
November 202510 µg/m³52 µg/m³74 µmol/m²50 µmol/m²
October 202511 µg/m³59 µg/m³83 µmol/m²61 µmol/m²
September 202513 µg/m³58 µg/m³91 µmol/m²77 µmol/m²
August 202520 µg/m³50 µg/m³103 µmol/m²113 µmol/m²
July 202522 µg/m³38 µg/m³103 µmol/m²95 µmol/m²
June 202521 µg/m³37 µg/m³111 µmol/m²91 µmol/m²
May 202521 µg/m³42 µg/m³89 µmol/m²81 µmol/m²
April 202515 µg/m³38 µg/m³87 µmol/m²55 µmol/m²
March 202512 µg/m³48 µg/m³74 µmol/m²48 µmol/m²
February 20258.4 µg/m³44 µg/m³69 µmol/m²44 µmol/m²
January 20259.8 µg/m³50 µg/m³65 µmol/m²47 µmol/m²
December 20248.8 µg/m³51 µg/m³69 µmol/m²61 µmol/m²
November 202411 µg/m³59 µg/m³78 µmol/m²65 µmol/m²
October 202414 µg/m³64 µg/m³78 µmol/m²63 µmol/m²
September 202416 µg/m³61 µg/m³94 µmol/m²85 µmol/m²
August 202421 µg/m³53 µg/m³108 µmol/m²93 µmol/m²
July 202424 µg/m³39 µg/m³112 µmol/m²94 µmol/m²
June 202421 µg/m³37 µg/m³98 µmol/m²92 µmol/m²
May 202422 µg/m³42 µg/m³94 µmol/m²92 µmol/m²
April 202415 µg/m³42 µg/m³86 µmol/m²73 µmol/m²
March 202411 µg/m³46 µg/m³69 µmol/m²61 µmol/m²
February 20249.1 µg/m³46 µg/m³64 µmol/m²55 µmol/m²
January 20248.5 µg/m³45 µg/m³53 µmol/m²40 µmol/m²

Over the last five years the NO2 column averaged 106 µmol/m² in winter against 65 µmol/m² in summer, and the SO2 column 96 µmol/m² against 46 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: 9.9 µg/m³2004: 10 µg/m³2005: 11 µg/m³2006: 11 µg/m³2007: 12 µg/m³2008: 12 µg/m³2009: 12 µg/m³2010: 13 µg/m³2011: 12 µg/m³2012: 13 µg/m³2013: 14 µg/m³2014: 13 µg/m³2015: 13 µg/m³2016: 13 µg/m³2017: 14 µg/m³2018: 14 µg/m³2019: 15 µg/m³2020: 15 µg/m³2021: 15 µg/m³2022: 15 µg/m³2023: 15 µg/m³2024: 15 µg/m³2025: 14 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
20039.9 µg/m³
200410 µg/m³
200511 µg/m³
200611 µg/m³
200712 µg/m³
200812 µg/m³
200912 µg/m³
201013 µg/m³
201112 µg/m³
201213 µg/m³
201314 µg/m³
201413 µg/m³
201513 µg/m³
201613 µg/m³
201714 µg/m³
201814 µg/m³
201915 µg/m³
202015 µg/m³
202115 µg/m³
202215 µg/m³
202315 µg/m³
202415 µg/m³
202514 µg/m³

Every municipality, ranked · Everything we hold for The Msunduzi · 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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