Wildfire smoke that hung over Toronto for several days has now cleared, resulting in a notable improvement in air quality for Canada's most populous city.

Environment Canada, which issued special air quality statements for Toronto multiple days this week, has no alerts in place for the city today.

The city has a "low-risk" Air Quality Health Index rating this morning.

Toronto experienced hazy skies and smoky air earlier this week that saw schools move recess inside and daycares suspend outdoor activities.

The City of Toronto also had outreach teams checking on people experiencing homelessness and opened temporary spaces at some homeless shelters.

Parts of northern Ontario are now experiencing the effects of wildfire smoke, with Environment Canada warning of high levels of air pollution in communities that include North Bay, Sudbury and Timmins.

In Alberta, the worst air quality is near Fort Chipewyan, which remains on an evacuation order as a nearby fire burns out of control. Wood Buffalo and Grande Prairie also have high-risk air quality forecasts.

Moderately bad air quality is forecast for Edmonton and Calgary today.

In British Columbia, air quality is expected to improve almost everywhere in the province except for Fort St. John.

The number of fires burning across the country fell slightly Thursday, but forecasts suggest smoke warnings will remain in parts of several provinces into the weekend.

Environment Canada has warned that people with lung or heart diseases, older adults, children, pregnant people and those who work outdoors are at a higher risk of experiencing health effects from the smoke.

However, the agency notes that wildfire smoke can be harmful to everyone's health "even at low concentrations."

Multiple health studies have linked wildfire smoke to serious health consequences including heart attacks, strokes and breathing problems.

The Canadian Interagency Forest Fire Centre said there were 431 fires burning on Thursday in nine provinces and two territories. That was down from 441 Wednesday, with Quebec extinguishing 10 fires since Wednesday morning.

The week's events prompted two debates in the House of Commons related to climate change and fires.

The Bloc and NDP accused the Liberals of claiming to be acting on climate while still subsidizing and approving the expansion of fossil-fuel projects. The Liberals blamed the Conservatives for pushing back on climate policies such as carbon pricing without offering alternatives.

More than 43,000 square kilometres have burned in Canada so far this year, making 2023 the second-worst year for fires on record. That's before the hottest months of the year have even begun.

In 2014, more than 46,000 square kilometres burned, the most ever in a single year. At the current pace, that total is expected to be passed this weekend.

This report by The Canadian Press was first published June 9, 2023.