Air Quality Index (AQI) Interpreter
Understand your local AQI reading.
Get health recommendations based on air quality level and sensitive groups.
AQI Assessment
The Air Quality Index (AQI) is a standardized scale from 0 to 500 that indicates how clean or polluted the air is.
AQI ranges:
| AQI | Level | Color | Health Concern |
|---|---|---|---|
| 0–50 | Good | Green | Air quality is satisfactory |
| 51–100 | Moderate | Yellow | Acceptable for most people |
| 101–150 | Unhealthy for Sensitive | Orange | Sensitive groups affected |
| 151–200 | Unhealthy | Red | Everyone may feel effects |
| 201–300 | Very Unhealthy | Purple | Health alert for all |
| 301–500 | Hazardous | Maroon | Emergency conditions |
What the AQI measures:
- PM2.5 — Fine particles (most health-relevant)
- PM10 — Coarse particles
- Ozone (O3) — Ground-level ozone
- NO2 — Nitrogen dioxide
- SO2 — Sulfur dioxide
- CO — Carbon monoxide
Sensitive groups include: Children, elderly, people with asthma, heart disease, or lung disease.