Smoke from northern Ontario forest fires will cause poor air quality and reduced visibility in Sarnia Monday, according to Environment and Climate Change Canada.

The extended forecast suggests unsettled weather midweek, with rain probabilities ranging from 30% to 60%. There is some uncertainty about the exact timing and placement of the rain, but meteorologists anticipate widespread cloud cover and precipitation potential Wednesday through Thursday.

Environment Canada urges residents to limit their time outdoors. But even when inside, most buildings can only reduce airborne pollutants by half.