Smoke from hundreds of wildfires burning in northern Ontario has spread across the province, leaving parts of Ontario with some of the worst air quality in the world on Wednesday according to the Weather Network.
The smoke has travelled more than 1,000 kilometres, creating hazy skies, reduced visibility and a noticeable smell of smoke across much of southern Ontario.
The wildfires followed days of extreme heat and dry conditions in the north, where hundreds of fires remain out of control.
Very poor air quality is expected across southern Ontario, with the smoky conditions likely lasting through much of Thursday.
Health officials say wildfire smoke can increase the risk of breathing problems, particularly for older adults, young children, pregnant people and anyone with asthma, heart disease or other respiratory conditions. Residents are encouraged to limit strenuous outdoor activities, keep windows and doors closed when possible, and use air conditioning or air filtration to reduce smoke exposure.
Conditions are expected to gradually improve by Friday as cooler weather moves into the province.
