If you plan to spend time outdoors, check the Air Quality Index (AQI) for your location. If the air quality is unhealthy, try to reduce the time you spend outside, or change your plans altogether.

Being exposed to polluted air can cause health problems, especially in children, older adults, and those who have heart or lung conditions.

Even if you're healthy, you may experience coughing, throat irritation, and shortness of breath when exposed to polluted air. Over time, repeated exposure can trigger asthma and other respiratory diseases.

WHAT DOES AQI MEASURE?
The Air Quality Index, which is updated daily, measures five major air pollutants:

WHAT DO THE AQI COLORS AND NUMBERS MEAN?
There are six AQI levels. Here's a brief summary of what each level means:

Green - Good (AQI 0-50)
Air quality is satisfactory.

Yellow - Moderate (AQI 51-100)
Air quality is acceptable, but there may be a moderate health concern for very sensitive individuals.

Orange - Unhealthy for Sensitive Groups (AQI 101-150)
The general public is not likely to be affected, but older adults, children, and those with heart and lung illnesses may experience adverse health effects.

Red - Unhealthy (AQI 151-200)
Everyone may begin to experience adverse health effects.

Purple - Very Unhealthy (AQI 201-300)
This would trigger a health alert signifying that everyone may experience more serious health effects.

Maroon - Hazardous (AQI greater than 300)
This would trigger a health warning. The entire population is likely to be affected.

Learn more about the Air Quality Index and find out what you can do to help keep the air clean.