Poor air quality is in the books for Butler County Monday afternoon, July 8, along with other areas near Pittsburgh, Philadelphia, Susquehanna Valley and Lehigh Valley due to conditions creating robust ozone development and formation into the code orange range.

The Department of Environmental Protection issued a Code Orange Air Quality Action Day Monday, indicating that air pollution will reach unhealthy levels for vulnerable groups.

The DEP encourages young children, the elderly, and those with respiratory problems, such as asthma, emphysema, and bronchitis, to limit outdoor activities during air quality action days.

Higher levels of ozone typically follow high temperatures and “an abundance of sunshine,” National Weather Service of Pittsburgh meteorologist Mike Kennedy said.

Another contributing factor of poor air quality could be lack of rain over the past couple of days, which would have allowed particulate matter to build up, he said.

Kennedy said temperatures will continue into the 90s through Wednesday, stating that residents can also expect high humidity this week.

The DEP recommends that residents in affected areas conserve electricity by setting air conditioning to a higher temperature, combine errands to reduce vehicle trips, limit engine idling and refuel vehicles after dusk.