Worst air pollution Union Buildings - Pretoria, today and tomorrow
Today (9 August): Air quality in Union Buildings is fair. PM2.5, NO2, and HCHO are fair; AQI, O3, SO2, and PM1 are medium; PM10 and CO are good. Pollution peaks around 8:00 AM (SO2: 44.2/100).
Tomorrow (10 August 2026): Air quality in Union Buildings is fair. PM2.5 decreases to good; O3 increases to fair; PM1 increases to fair; all other pollutants stay as today. Pollution peaks around 8:00 PM (SO2: 40.3/100). Airmine updates local air quality forecasts four times daily.
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Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team
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Union Buildings lies roughly 50 km north-northeast of Johannesburg. Vehicle traffic and government, finance, and commercial operations are the main contributors to air quality conditions at Union Buildings, set on the dry Highveld plateau. Winter mornings can see emissions concentrate under a temperature inversion, while the wetter, windier summer months typically bring clearer air to the wider district. Much of the surrounding Highveld sees broadly the same seasonal pattern.
Today - 9 August | Pollution peaks at 08:00
AQI:
Medium
44.2/100
PM2.5 (fine particles):
Fair
33.2/100
PM10 (coarse particles):
Good
9.3/100
NO2 (nitrogen dioxide):
Fair
32.8/100
O3 (ozone):
Medium
41.9/100
SO2 (sulfur dioxide):
Medium
44.2/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Fair
27.7/100
PM1 (ultrafine particles):
Medium
40.3/100
Levels show the poorest local air quality during the day
Tomorrow - 10 August | Pollution peaks at 20:00
AQI:
Medium
40.3/100
PM2.5 (fine particles):
Good
16.5/100
PM10 (coarse particles):
Good
4.5/100
NO2 (nitrogen dioxide):
Fair
27.7/100
O3 (ozone):
Fair
26.5/100
SO2 (sulfur dioxide):
Medium
40.3/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Fair
20.1/100
PM1 (ultrafine particles):
Fair
21.9/100
Other Landmarks in Pretoria
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Frequently Asked Questions
Is air quality bad in Union Buildings right now?
On 9 August 2026, overall air quality in Union Buildings is fair. PM2.5 is the main pollutant at 33.2/100. Pollution peaks around 8:00 AM (SO2: 44.2/100).
Will air quality be worse tomorrow in Union Buildings?
On 10 August 2026, air quality conditions in Union Buildings will be similar to today, with NO2 forecast at fair at 27.7/100. Pollution peaks around 8:00 PM (SO2: 40.3/100).
When is air pollution at its worst in Union Buildings?
The worst air quality at Union Buildings shows up on calm winter mornings, when emissions tied to government, finance, and commercial operations settle under the kind of low inversion that's common across the Highveld. That pattern breaks once the summer rains and stronger winds arrive from November onward. This is a familiar pattern across much of the Highveld.
Are air quality levels in Union Buildings based on measurements or forecasts?
It is forecasts derived by downscaling forecasts provided by EU’s Copernicus Atmosphere Monitoring Service (CAMS) by taking into account local conditions such as traffic patterns. CAMS bases its forecast on satellite measurements of particles and chemical compounds in the atmosphere. Airmine’s services were developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team.
Why doesn’t the forecast always reflect wildfire impacts?
Airmine’s forecast uses CAMS (Copernicus Atmosphere Monitoring Service) as its background atmospheric model. While CAMS includes wildfire emissions, these are derived from satellite observations and are not available in real time. During rapidly evolving wildfire events, there may therefore be a delay before increased emissions are incorporated into the model. As a result, the forecast may temporarily underestimate PM₂.₅ and other pollutants associated with wildfire smoke.
During rapidly evolving wildfire events, CAMS may lag by approximately 1–2 days before increased wildfire emissions are fully represented, which can lead to temporary underestimation of PM₂.₅ concentrations in Airmine’s forecast.
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Data provided by Airmine — Last update: 10 August 2026 at 02:34 CEST (Data is updated four times daily.)
This forecast is produced independently using Airmine's own atmospheric data and models.
Unless explicitly made clear, the content on this site has not been paid for by external organisations and is Airmine's sole responsibility.
Disclaimer: Forecasts are provided for informational purposes only and should not be relied upon as medical advice. Actual pollen and air quality conditions may vary from the forecast. If you have allergies, asthma, or another medical condition, consult a healthcare professional. Please see our Terms of Service for important information about limitations of liability.
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