Understanding the air quality index (AQI)
| AQI | Level | What to do |
|---|---|---|
| 0–50 | Good (राम्रो) | Air quality is good. Enjoy outdoor activities. |
| 51–100 | Moderate (मध्यम) | Acceptable. Very sensitive people should limit long outdoor exertion. |
| 101–150 | Unhealthy for sensitive groups (संवेदनशीलका लागि अस्वस्थ) | Children, older people and people with asthma or heart disease should limit outdoor exertion. |
| 151–200 | Unhealthy (अस्वस्थ) | Everyone should reduce long or heavy outdoor exertion. Consider a mask outdoors. |
| 201–300 | Very unhealthy (धेरै अस्वस्थ) | Avoid outdoor exertion. Keep windows closed and wear an N95 mask outside. |
| 301+ | Hazardous (खतरनाक) | Stay indoors. Everyone should avoid outdoor activity. |
Kathmandu Valley’s air is usually worst in winter and spring, when dust, vehicle smoke and forest fires combine with still air. An N95 mask helps on bad days.