Air quality by country
Air quality in Czechia today
Updated
Good: average US AQI 36 across 4 cities Worst now: Brno (47); cleanest: Most (26).
Live US AQI, PM2.5 and ozone for cities across Czechia, ranked from most polluted to cleanest.
- Average US AQI
- 36 Good
- Most polluted now
- Brno AQI 47
- Cleanest now
- Most AQI 26
- Cities above 100
- 0 unhealthy for sensitive groups or worse
Air quality in Czechia today
Right now the modelled air quality in Czechia averages a US AQI of 36 (Good) across the 4 cities we track. By category: 4 Good (of 4).
That is 29 points better than the worldwide average of 65 across 3,909 cities.
Brno has the worst air at 47 with PM2.5 at 3.9 µg/m³, while Most is cleanest at 26. No tracked city is above 100, the level where sensitive groups are advised to cut back outdoors.
Czechia cities by AQI (most polluted first)
| City | Region | US AQI | Category | PM2.5 µg/m³ | Ozone µg/m³ |
|---|---|---|---|---|---|
| Brno | South Moravian | 47 | Good | 3.9 | 54 |
| Ostrava | Moravian-Silesian Region | 42 | Good | 5.9 | 53 |
| Prague | Prague | 28 | Good | 3.4 | 61 |
| Most | Ústí nad Labem Region | 26 | Good | 3.6 | 54 |
What the US AQI numbers mean
| US AQI | Category | What it means |
|---|---|---|
| 0-50 | Good | Air quality is satisfactory and poses little or no risk; a good time for outdoor activity. |
| 51-100 | Moderate | Acceptable for most people. Unusually sensitive people should consider shortening long or heavy exertion outdoors. |
| 101-150 | Unhealthy for Sensitive Groups | People with heart or lung disease, older adults, children and teens should cut back on prolonged or heavy exertion outdoors. |
| 151-200 | Unhealthy | Everyone should reduce prolonged or heavy exertion outdoors; sensitive groups should avoid it and keep windows closed. |
| 201-300 | Very Unhealthy | Health alert: everyone should avoid prolonged or heavy exertion outdoors, and sensitive groups should stay indoors. |
| 301-500 | Hazardous | Emergency conditions: everyone should avoid all outdoor physical activity and stay indoors with filtered air if possible. The scale tops out at 500; heavier dust or smoke is shown as 500. |
Modelled by CAMS (Copernicus) via Open-Meteo, refreshed twice a day; read hour by hour from the forecast.
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Data: Open-Meteo Air Quality API, Copernicus Atmosphere Monitoring Service (CAMS).