Air Quality Index

Air Quality Index

How does the Air Quality Index work?
The following information is taken from the Environmental Protection Agency (EPA) document entitled "Air Quality Index, A Guide to Air Quality and Your Health." You can think of the Air Quality Index (AQI) as a yardstick that runs from 0 to 500. The higher the AQI value, the greater the level of air pollution and the greater the health danger. For example, an AQI value of 50 represents good air quality and little potential to affect public health, while an AQI value over 300 represents hazardous air quality.

An AQI value of 100 generally corresponds to the national air quality standard for the pollutant, which is the level EPA has set to protect public health. So, AQI values below 100 are generally thought of as satisfactory. When AQI values are above 100, air quality is considered to be unhealthy - at first for certain sensitive groups of people, then for everyone as AQI values get higher.

Full copy of "AQI - A Guide to Air Quality and Your Health" and an updated "Air Quality Guide for Particle Pollution" section.

Kids can also find additional information on the air quality index at the Environmental Proection Agency’s website at

What is Rapid City’s Air Quality Index?
The South Dakota Department of Environment and Natural Resources’ Air Quality Program collects information for ozone and PM 2.5 from the Credit Union Site in Rapid City on an hourly basis.  The information is reported to AirNow for use in the national AQI map found on the AirNow website

If you are visiting another city and would like to know more about the air quality you can access the Environmental Protection Agency website at

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