Several western Pennsylvania counties, including Butler, are under an Air Quality Alert.
This means there could potentially be high levels of fine particulate matter in the air bought on by a calm, colder air was trapped below unseasonably warm air in the middle 60s, according to the Pennsylvania Department of Environmental Protection. The conditions brought ozone concentrations to the code Orange level.
Young children, the elderly and those with respiratory problems, including asthma, emphysema and bronchitis, should limit their time outdoors because they are especially vulnerable to the effects of air pollution.
Conditions are expected to improve by late Tuesday when a cold front is due in. The Cold Orange Air Quality Action Day has been issued for Butler, Allegheny, Westmoreland, Beaver, Armstrong, Washington, and Fayette counties.