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Air in Ndwedwe

Air in 2025 (modelled): nitrogen dioxide near the ground averaged 14 µg/m³, 1.4 times WHO’s guideline of 10; winters 21 µg/m³, summers 9.1 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 20259.2 µg/m³51 µg/m³64 µmol/m²47 µmol/m²
November 20259.6 µg/m³57 µg/m³75 µmol/m²52 µmol/m²
October 202510 µg/m³60 µg/m³82 µmol/m²67 µmol/m²
September 202512 µg/m³61 µg/m³89 µmol/m²91 µmol/m²
August 202519 µg/m³52 µg/m³110 µmol/m²132 µmol/m²
July 202521 µg/m³38 µg/m³111 µmol/m²106 µmol/m²
June 202521 µg/m³38 µg/m³117 µmol/m²99 µmol/m²
May 202523 µg/m³41 µg/m³97 µmol/m²86 µmol/m²
April 202515 µg/m³41 µg/m³92 µmol/m²61 µmol/m²
March 202512 µg/m³46 µg/m³74 µmol/m²47 µmol/m²
February 202511 µg/m³44 µg/m³80 µmol/m²46 µmol/m²
January 20259.5 µg/m³46 µg/m³65 µmol/m²44 µmol/m²
December 20248.3 µg/m³53 µg/m³68 µmol/m²67 µmol/m²
November 202411 µg/m³63 µg/m³81 µmol/m²76 µmol/m²
October 202413 µg/m³67 µg/m³77 µmol/m²65 µmol/m²
September 202415 µg/m³65 µg/m³98 µmol/m²106 µmol/m²
August 202418 µg/m³57 µg/m³113 µmol/m²104 µmol/m²
July 202423 µg/m³41 µg/m³114 µmol/m²94 µmol/m²
June 202421 µg/m³38 µg/m³108 µmol/m²98 µmol/m²
May 202422 µg/m³43 µg/m³94 µmol/m²95 µmol/m²
April 202416 µg/m³42 µg/m³87 µmol/m²76 µmol/m²
March 20249.9 µg/m³44 µg/m³67 µmol/m²62 µmol/m²
February 20248.3 µg/m³45 µg/m³59 µmol/m²54 µmol/m²
January 20248.4 µg/m³43 µg/m³54 µmol/m²39 µmol/m²

Over the last five years the NO2 column averaged 113 µmol/m² in winter against 65 µmol/m² in summer, and the SO2 column 108 µmol/m² against 47 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: 9.2 µg/m³2004: 9.8 µg/m³2005: 10 µg/m³2006: 11 µg/m³2007: 11 µg/m³2008: 11 µg/m³2009: 11 µg/m³2010: 12 µg/m³2011: 11 µg/m³2012: 12 µg/m³2013: 13 µg/m³2014: 12 µg/m³2015: 12 µg/m³2016: 13 µg/m³2017: 13 µg/m³2018: 13 µg/m³2019: 14 µg/m³2020: 14 µg/m³2021: 14 µg/m³2022: 15 µg/m³2023: 15 µg/m³2024: 14 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
20039.2 µg/m³
20049.8 µg/m³
200510 µg/m³
200611 µg/m³
200711 µg/m³
200811 µg/m³
200911 µg/m³
201012 µg/m³
201111 µg/m³
201212 µg/m³
201313 µg/m³
201412 µg/m³
201512 µg/m³
201613 µg/m³
201713 µg/m³
201813 µg/m³
201914 µg/m³
202014 µg/m³
202114 µg/m³
202215 µg/m³
202315 µg/m³
202414 µg/m³
202514 µg/m³

See it in the Copernicus Browser, the European Space Agency’s free viewer, on the newest image: Sentinel-5P, nitrogen dioxide · Sentinel-5P, sulphur dioxide. These are Sentinel-5P’s observed columns for one day, not our modelled yearly figures; days with cloud have gaps.

Every municipality, ranked · Everything we hold for Ndwedwe · 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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