This data, supplied by the Environmental Division's Bureau of Air, have been obtained from automated instruments and have not been subjected to a quality assurance review to determine their accuracy. They are presented for public awareness and should not be considered final until certified by our staff. Conditions such as power outages and equipment malfunctions can produce invalid data. Quality assured data can be obtained by contacting the Bureau of Air.
This webpage provides the most current Air Quality Index (AQI) and hourly averaged data available. For example, values shown for the noon hour are based on measurements taken from noon to 1 pm. The noon average will not be calculated until after 1 pm. This results in an apparent one-hour time lag in the data. We present our data in Central Standard Time. Daylight Savings introduces another apparent one-hour time lag in the data.
Please note that not all parameters are measured at all sites. The values in the site squares are AQI values. The AQI/Air Monitoring Data pages are best viewed with Internet Explorer.