| Green |
Good |
0 to 50 |
Air quality is satisfactory, and air pollution poses little or no risk. |
| Yellow |
Moderate |
51 to 100 |
Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. |
| Orange |
Unhealthy for Sensitive Groups |
101 to 150 |
Members of sensitive groups may experience health effects. The general public is less likely to be affected. |
| Red |
Unhealthy |
151 to 200 |
Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. |
| Purple |
Very Unhealthy |
201 to 300 |
Health alert: The risk of health effects is increased for everyone. |
| Maroon |
Hazardous |
301 and higher |
Health warning of emergency conditions: everyone is more likely to be affected. |