About Wheezair
See what you're breathing
Wheezair is a live map of the air the world breathes. Each light is one of 5,350 cities, breathing with its air: a slow, deep breath when the air is clean, a quick, shallow one when it's polluted. Colour shows the European Air Quality Index; the glow grows with fine particles (PM2.5).
You can scrub through the last two weeks hour by hour, look four days ahead, replay up to a year of daily averages, colour the map by a single pollutant, find any city and share exactly what you see.
The European Air Quality Index
The index (EAQI) is defined by the European Environment Agency. It takes the worst of five pollutants — PM2.5, PM10, nitrogen dioxide (NO₂), ozone (O₃) and sulphur dioxide (SO₂) — on a common scale:
| Good | 0–20 | Clean air. A great time to be outside. |
| Fair | 20–40 | Fine for almost everyone. |
| Moderate | 40–60 | Sensitive people may want to take it easier outdoors. |
| Poor | 60–80 | Consider less intense outdoor activity, especially if you have heart or lung conditions. |
| Very poor | 80–100 | Cut down time and effort outdoors; sensitive groups should avoid it. |
| Extremely poor | 100+ | Avoid outdoor activity and keep windows closed where you can. |
Where the data comes from
All values are model estimates from the Copernicus Atmosphere Monitoring Service (CAMS), the EU's atmosphere programme, served by Open-Meteo. CAMS combines satellite observations, ground stations and weather models into a forecast of the whole atmosphere: about 11 km detail over Europe and 40 km elsewhere.
Wheezair downloads a fresh forecast for every city once a day and keeps hourly values for two weeks and daily averages for good. Because these are model values, they describe a city's general air, not a single street; official monitoring stations can differ.
Questions and answers
- What does the breathing mean?
- Each city's pulse follows its air quality: clean air breathes slowly and deeply (about 5 seconds per breath), polluted air quickly and shallowly (down to about a second).
- How often is the data updated?
- Every city gets a new CAMS forecast once a day (after 09:00 UTC), covering the next four days hour by hour. The map moves to the current hour automatically.
- Is this measured data?
- No — it's model data from Copernicus CAMS, which blends satellite and station observations with weather models. It is consistent worldwide, but local measurements can differ, especially next to busy roads or factories.
- Which cities are included?
- 5,350 cities from GeoNames chosen so every inhabited region is covered: at most one point per 100 km worldwide, 40 km in Europe and 15 km in Poland — the most populous city in each area wins.
- Is Wheezair free?
- Yes. It's free to use, with no account. It may show ads to cover server costs.
Open data
The numbers are free to reuse under CC BY 4.0 (credit Open-Meteo, Copernicus CAMS and Wheezair). A small JSON API powers the map: /api/search?q=krakow, /api/point/<id>?res=hour|day, /api/snapshot?res=hour&at=now. Please be gentle with it.