World Air Quality Map
The colors show the air quality index across the whole world, hour by hour. Move the slider to see how the air is expected to change over the days ahead, and switch pollutants to see which one is pushing the index up.
The map shows the US air quality index, the same 0 to 500 scale as the numbers on the city pages. Pick a single pollutant and the colors show the index value for that pollutant on its own. The map and the city pages update at slightly different times, so a city near the edge of a band can show one band away from the value on its own page.
Everything on this map is a forecast, including the hours that have already passed. None of it is a reading from a monitoring station. It is also two forecasts stitched together, one for Europe and one for the rest of the world, and they do not always agree where they meet. The section below explains how that works.
Air quality forecasts from the Copernicus Atmosphere Monitoring Service (CAMS), via Open-Meteo. More about the data.
Highest right now
Ranked from the major cities on this site, using each city's forecast for the current hour. Plenty of places with worse air are not on this list. Cities inside the detailed European forecast area are ranked from that forecast and cities outside it from the worldwide one, so the two are not strictly comparable.
How this map is made
Two forecasts feed this map. Over Europe it uses the European one, which works in squares of about 11 km (7 miles), so cities stand out from the land around them. Everywhere else it uses the worldwide one, in squares of about 45 km (28 miles). Where the two meet you can often see a straight edge, because they do not always agree.
Questions about this map
What do the colors mean?
They are the six bands of the US air quality index. Green is good, 0 to 50. Yellow is moderate, 51 to 100. Orange is unhealthy for sensitive groups, 101 to 150. Red is unhealthy, 151 to 200. Purple is very unhealthy, 201 to 300. Maroon is hazardous, 301 and above. The color key sits under the map.
How often does the map change?
The map is redrawn when a new forecast arrives, usually twice a day, and it steps to the next hour on the hour. The slider runs from the current hour to the end of the forecast.
How far ahead does it go?
The worldwide forecast covers five days from midnight UTC, so depending on the time of day the slider offers between four and five days ahead. The detailed European one reaches about four days. After that, Europe is drawn from the worldwide forecast like everywhere else. The further ahead you look, the less certain the forecast is, which is true of any weather or air quality forecast.
Why is there a straight line across the map?
That line is the border between the two forecasts this map uses. They do not always agree, so where they meet the difference shows up as an edge. It is a real difference between the forecasts, not a glitch in the map.
Why does Europe look sharper than the rest of the map?
The European forecast works in squares of about 11 km, so it can tell a city apart from the countryside around it. The worldwide one works in squares of about 45 km, which blurs a city into its whole region. The detailed forecast covers Europe plus the North African coast, Turkey and the Levant, and it is the one the city pages here use, so inside that area the map and a city page are drawing on the same forecast.
Are these real measurements from air quality monitors?
No. Every color on this map comes from an atmospheric forecast model, including the hours that have already passed. None of it is a reading from a monitoring station near you.
