Smoke from the raging wildfires in Canada is back.

The Pennsylvania Department of Environmental Protection declared Monday a “Code Orange” air quality action day while the National Weather Service issued an air quality alert that ran through midnight Monday night.

“A code ORANGE Air Quality Alert means that air pollution concentrations within the region may become unhealthy for sensitive groups,” the alert from the National Weather Service explained. “Sensitive groups include children, people suffering from asthma, heart disease or other lung diseases and the elderly.

“The effects of air pollution can be minimized by avoiding strenuous activity or exercise outdoors.”

According to airnow.gov, the AQI in Erie, the closest tracking station, was 137.

Guidance for everyone was to “keep outdoor activities light and short.”

According to the DEP, residents and businesses in the areas affected are “strongly encouraged” to reduce air pollution by avoiding open burning and using gas-powered lawn and garden equipment.”