| Good | 0 to 50 | No health impacts are expected when air quality is in this range. |
| Moderate | 51 to 100 | Unusually sensitive people should consider limiting prolonged outdoor exertion. |
Unhealthy for Sensitive Groups (Alert) | 101 to 150 | Active children and adults, and people with respiratory disease, such as asthma, should limit prolonged outdoor exertion. |
| Unhealthy (Alert) | 151 to 200 | Active children and adults, and people with respiratory disease, such as asthma, should avoid prolonged outdoor exertion; everyone else, especially children, should limit prolonged outdoor exertion. |
Very Unhealthy (Alert) | 201 to 300 | Active children and adults, and people with respiratory disease, such as asthma, should avoid all outdoor exertion; everyone else, especially children, should limit outdoor exertion. |
Hazardous (Alert) | 301 to 500 | Health alert: Everyone may experience more serious health effects. |