Unmapped Dataworks

Free tools · From a European air-quality model

Air in Bojanala

Air in 2025 (modelled): nitrogen dioxide near the ground averaged 18 µg/m³, 1.8 times WHO’s guideline of 10; winters 24 µg/m³, summers 11 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 202512 µg/m³44 µg/m³58 µmol/m²52 µmol/m²
November 202511 µg/m³47 µg/m³66 µmol/m²53 µmol/m²
October 202515 µg/m³58 µg/m³84 µmol/m²72 µmol/m²
September 202516 µg/m³56 µg/m³83 µmol/m²86 µmol/m²
August 202525 µg/m³51 µg/m³95 µmol/m²91 µmol/m²
July 202527 µg/m³40 µg/m³103 µmol/m²98 µmol/m²
June 202526 µg/m³38 µg/m³118 µmol/m²102 µmol/m²
May 202526 µg/m³42 µg/m³120 µmol/m²124 µmol/m²
April 202517 µg/m³37 µg/m³87 µmol/m²81 µmol/m²
March 202517 µg/m³44 µg/m³80 µmol/m²79 µmol/m²
February 202511 µg/m³42 µg/m³78 µmol/m²80 µmol/m²
January 202512 µg/m³44 µg/m³67 µmol/m²71 µmol/m²
December 20249.7 µg/m³49 µg/m³61 µmol/m²56 µmol/m²
November 202412 µg/m³60 µg/m³72 µmol/m²72 µmol/m²
October 202414 µg/m³68 µg/m³86 µmol/m²100 µmol/m²
September 202416 µg/m³58 µg/m³85 µmol/m²87 µmol/m²
August 202423 µg/m³51 µg/m³95 µmol/m²88 µmol/m²
July 202427 µg/m³38 µg/m³103 µmol/m²70 µmol/m²
June 202428 µg/m³38 µg/m³129 µmol/m²116 µmol/m²
May 202431 µg/m³43 µg/m³128 µmol/m²142 µmol/m²
April 202417 µg/m³41 µg/m³83 µmol/m²83 µmol/m²
March 202414 µg/m³46 µg/m³82 µmol/m²85 µmol/m²
February 202412 µg/m³46 µg/m³67 µmol/m²74 µmol/m²
January 202411 µg/m³51 µg/m³65 µmol/m²80 µmol/m²

Over the last five years the NO2 column averaged 112 µmol/m² in winter against 67 µmol/m² in summer, and the SO2 column 102 µmol/m² against 68 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: 11 µg/m³2004: 11 µg/m³2005: 11 µg/m³2006: 12 µg/m³2007: 12 µg/m³2008: 14 µg/m³2009: 14 µg/m³2010: 14 µg/m³2011: 15 µg/m³2012: 14 µg/m³2013: 13 µg/m³2014: 14 µg/m³2015: 14 µg/m³2016: 15 µg/m³2017: 16 µg/m³2018: 16 µg/m³2019: 18 µg/m³2020: 17 µg/m³2021: 17 µg/m³2022: 17 µg/m³2023: 17 µg/m³2024: 18 µg/m³2025: 18 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
200311 µg/m³
200411 µg/m³
200511 µg/m³
200612 µg/m³
200712 µg/m³
200814 µg/m³
200914 µg/m³
201014 µg/m³
201115 µg/m³
201214 µg/m³
201313 µg/m³
201414 µg/m³
201514 µg/m³
201615 µg/m³
201716 µg/m³
201816 µg/m³
201918 µg/m³
202017 µg/m³
202117 µg/m³
202217 µg/m³
202317 µg/m³
202418 µg/m³
202518 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 Bojanala · 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.

Unmapped Dataworks