What is in the air over Pretoria
Micrograms per cubic metre — how much of each is floating in a box of air. The overall index is the worst of them, so one high pollutant is what you are feeling.
- PM2.5 23 µg/m³ moderateSmoke and dust fine enough to reach deep into your lungs — veld fires, braai smoke, coal stoves, traffic.
- PM10 23 µg/m³ moderateCoarser dust — gravel roads, mine dumps, dry veld and building sites. It sticks in your nose and throat.
- Nitrogen dioxide 3.5 µg/m³ lowTraffic fumes. Highest next to busy roads in the rush hours.
- Ozone 201 µg/m³ highSunshine smog: fumes cooked by strong sun. Worst on hot, still afternoons, not first thing in the morning.
How to read these numbers
Overhead uses the European Air Quality Index, the scale most phone weather apps show: up to 20 is good, 20 to 40 fair, 40 to 60 moderate, 60 to 80 poor, 80 to 100 very poor, and above 100 extremely poor. The index is the worst single pollutant, not an average of them — which is the honest way round, because it is the worst one you are breathing.
These readings come from a model that combines satellite observations with emissions and weather data, not from a monitoring station in your street. A ground monitor a few kilometres away can legitimately read differently, and it usually will right beside a busy road, downwind of a fire, or in a valley holding cold air. Treat this as the shape of the day rather than a measurement of your doorstep.
The next 24 hours
Air quality moves with the day: traffic peaks morning and evening, ozone builds through a hot afternoon, and smoke settles under cold, still air overnight.
| Hour | AQI | Level |
|---|---|---|
| 13:00 | 121 | extremely poor |
| 14:00 | 121 | extremely poor |
| 15:00 | 120 | extremely poor |
| 16:00 | 117 | extremely poor |
| 17:00 | 109 | extremely poor |
| 18:00 | 94 | very poor |
| 19:00 | 78 | poor |
| 20:00 | 71 | poor |
| 21:00 | 72 | poor |
| 22:00 | 75 | poor |
| 23:00 | 76 | poor |
| 00:00 | 69 | poor |
| 01:00 | 60 | moderate |
| 02:00 | 55 | moderate |
| 03:00 | 49 | moderate |
| 04:00 | 46 | moderate |
| 05:00 | 44 | moderate |
| 06:00 | 44 | moderate |
| 07:00 | 44 | moderate |
| 08:00 | 44 | moderate |
| 09:00 | 45 | moderate |
| 10:00 | 60 | moderate |
| 11:00 | 66 | poor |
| 12:00 | 70 | poor |
Why the air changes here
Winter is the Highveld's air-quality season, and the reason is physical: on cold, still nights a temperature inversion forms, capping the surface with a lid of warmer air so smoke from domestic coal and wood fires, vehicles and industry cannot disperse. The problem is severe enough that government has declared two of South Africa's national air-quality priority areas here — the Vaal Triangle Airshed and the Highveld Priority Area.
Who should take care in Pretoria today
Skip the outdoor workout, keep windows and doors closed, and keep kids’ outdoor time short. Keep your asthma pump close if you use one.
More for Pretoria
Air quality nearby
Overhead is a free guide built on live open weather data from Open-Meteo (CC BY 4.0). It is advisory only — for official warnings and emergencies, follow the South African Weather Service.