Sitting on a park bench in downtown Toronto, Maria Lee flicked through the photos on her phone to show how smoke had occluded the view from her high-rise apartment near Lake Ontario.
“I like a blue sky, no pollution and sunshine,” Ms. Lee said, pointing at the gray smudge on the horizon in the pictures. “Now everything is dirty.”
As the deep smog lifted over Ottawa, the national capital, on Thursday, changing winds caused the air quality in Toronto, Canada’s largest city, to visibly deteriorate. The government agency Environment and Climate Change Canada gave downtown Toronto a “moderate risk” rating on its air quality scale at midday Thursday, but forecast that conditions would worsen as the day continued and move the city to the “high risk” level.
But that was not as severe as had been anticipated. Steven Flisfeder, a warning preparedness meteorologist at the weather service of Environment and Climate Change Canada, said that the intensity of the smoke wafting from the northeast part of the province had been curbed by increased humidity and a bit of rain and cloud cover near wildfire areas.
“That’s going to help flush out the contaminants from the air a little bit,” Mr. Flisfeder said. “That should improve the conditions on the air quality side.”
Ms. Lee said that while the city looked less appealing, she had found that Thursday’s milder temperatures meant that the smoke actually had less of an effect on her breathing than it had earlier in the week. Nevertheless, she had an N95 mask slipped over one of her wrists. And she said that the smoke has exacerbated the asthma of one of her close friends.
In the vast square in front of Toronto’s city hall, Patrick Junior Bradley, a bicycle messenger who lives in the suburban district of Scarborough, noted the absence of the usual flocks of tourists. It was unclear whether that was related to warnings from health officials to stay indoors. Few people on downtown streets were wearing masks, however.
And Mr. Bradley, who is known as P.J., said he had no qualms about cycling through the haze.
“It doesn’t worry me,” he said. “I just hope wherever the fire is that people are safe.”