Published on April 28, 2025
The Lincoln-Lancaster County Health Department (LLCHD) today announced that incorrect high Air Quality Index (AQI) values for the Lincoln area reported on Saturday, April 26, and Sunday, April 27, were due to a malfunctioning air monitor that measures ground-level ozone.
“Ground-level ozone is a pollutant that is not emitted directly by any equipment or processes. It is a pollutant that is formed through a chemical reaction in the atmosphere. It typically requires significant heat and sunlight to reach unhealthy levels, and weather conditions in the Lincoln area were not favorable to produce such high ozone values,” said Gary Bergstrom, LLCHD Air Quality Section Supervisor. “An error code on the malfunctioning monitor indicated to us that the data produced by the monitor on Saturday and Sunday was not reliable.”
Bergstrom said that ozone readings from monitors in Omaha showed good air quality throughout the weekend and that Lincoln’s ozone levels were likely similar.
To ensure continuous air quality monitoring, LLCHD took the malfunctioning monitor offline for maintenance and replaced it with a backup monitor. The monitor taken offline will undergo a full series of quality assurance checks before being returned to service.
Although the issue with the monitor was addressed, Bergstrom explained that there was a substantial time lag before corrected data was reflected on various air quality reporting platforms. As a result, outdated or inaccurate AQI readings may have remained visible to the public for some time after the problem was resolved. Bergstrom said that such monitor errors are very rare.
The AQI for Lincoln is updated hourly and is available at airnow.gov.