What is in the air over Cape Town
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 12 µg/m³ moderateSmoke and dust fine enough to reach deep into your lungs — veld fires, braai smoke, coal stoves, traffic.
- PM10 17 µg/m³ lowCoarser dust — gravel roads, mine dumps, dry veld and building sites. It sticks in your nose and throat.
- Nitrogen dioxide 4.1 µg/m³ lowTraffic fumes. Highest next to busy roads in the rush hours.
- Ozone 70 µg/m³ moderateSunshine 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 | 34 | fair |
| 14:00 | 35 | fair |
| 15:00 | 34 | fair |
| 16:00 | 33 | fair |
| 17:00 | 32 | fair |
| 18:00 | 31 | fair |
| 19:00 | 31 | fair |
| 20:00 | 30 | fair |
| 21:00 | 28 | fair |
| 22:00 | 27 | fair |
| 23:00 | 26 | fair |
| 00:00 | 24 | fair |
| 01:00 | 23 | fair |
| 02:00 | 23 | fair |
| 03:00 | 22 | fair |
| 04:00 | 22 | fair |
| 05:00 | 21 | fair |
| 06:00 | 21 | fair |
| 07:00 | 23 | fair |
| 08:00 | 26 | fair |
| 09:00 | 30 | fair |
| 10:00 | 31 | fair |
| 11:00 | 31 | fair |
| 12:00 | 30 | fair |
Why the air changes here
For most of the year the wind keeps Cape air clean. Two things spoil it. On still, cold winter mornings an inversion traps vehicle exhaust — diesel in particular — and smoke from wood fires under a visible brown haze layer over the low-lying areas. In late summer, from January to March, it is smoke: this is fynbos fire season, and a mountain fire upwind can put the whole city under smoke for a day or two.
Who should take care in Cape Town today
Good day for a run, a ride or letting the kids play outside as long as they like.
More for Cape Town
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.