0-50 (GREEN): Air quality is satisfactory, and air pollution poses little or no risk with 24 hours of exposure.

51-100 (YELLOW): Air quality is acceptable. However, there may be a risk for some people with 24 hours of exposure, particularly those who are unusually sensitive to air pollution

101-150 (ORANGE): Members of sensitive groups may experience health effects with 24 hours of exposure. The general public is less likely to be affected.

151-200 (RED): Some members of the general public may experience health effects with 24 hours of exposure, members of sensitive groups may experience more serious health effects.

201-300 (PURPLE): Health ALERT: The risk of health effects is increased for everyone with 24 Hours of exposure.

300 + (BROWN): Health warning emergency conditions: everyone is more likely to be affected with 24 hours of exposure.