Environment Canada has issued a Special Air Quality Statement for Toronto, warning that drifting wildfire smoke is expected to cause poor air quality and reduced visibility throughout the day.

“Air quality and visibility due to wildfire smoke can fluctuate over short distances and can vary considerably from hour to hour,” Environment and Climate Change Canada (ECCC) said in its statement.

The smoke is expected to remain over the northern and central Plains of the United States for the next couple of days, according to meteorologists.