By Friday night, the band of poor quality air had moved eastward. On Saturday morning, all continuous monitors were reporting moderate or good levels.

Poor air quality is often associated with stationary (a.k.a. stagnant) high pressure frontal systems. As these stagnant systems move eastward, cleaner, low-pressure air often follows behind it.

The University Hygienic Laboratory collects samples of ambient air from stations throughout the state and reports the data to the IDNR. When necessary, the IDNR will issue air quality alerts to inform Iowans with compromised respiratory systems or heart disease, as well as the elderly and children, to limit their prolonged exertion outdoors until the air quality improves.

There are several ways to monitor Iowa's air in real time (or near real time). Catch the current readings or easily scroll back in days or months to gauge the air quality index from the UHL Ambient Air Quality web page. The EPA provides the national view of air quality and the forecast from coast to coast.