Toronto Records World's Worst Air Quality as Wildfire Smoke Blankets City

Thick smoke from ongoing wildfires has blanketed Toronto, pushing the city's air quality to the worst in the world on Wednesday morning, according to global air quality monitoring platform IQAir.

Environment and Climate Change Canada has issued an Orange Air Quality Alert for Toronto as smoke from wildfires burning in northwestern Ontario continues to drift south, covering the Greater Toronto Area in a dense haze.

The weather agency warned that poor air quality could persist across many parts of the region through Thursday.

Health Risks Increase as Smoke Intensifies

Officials said health risks rise as smoke concentrations increase and urged residents to limit unnecessary time outdoors, avoid strenuous physical activity, and reschedule outdoor exercise whenever possible.

According to IQAir, Toronto ranked as the city with the world's poorest air quality at around 8:00 a.m. Wednesday.

Common Symptoms of Smoke Exposure

Health authorities said exposure to wildfire smoke may cause:

• Irritation of the eyes, nose, and throat
• Headaches
• Mild coughing

More serious symptoms may include:

• Shortness of breath or wheezing
• Chest pain
• Persistent or severe coughing

Residents experiencing severe symptoms are advised to seek medical attention immediately.

Vulnerable Groups

Health officials said the following groups face a higher risk from wildfire smoke:

• Adults aged 65 and older
• Pregnant women
• Infants and young children
• People with chronic illnesses or respiratory conditions

Public Health Advice

Authorities are urging residents to:

• Stay indoors as much as possible.
• Keep windows and doors closed.
• Minimize the amount of time spent outside.
• Stay in cool, air-conditioned spaces where available.
• Drink plenty of water, especially during the ongoing heatwave.
• Outdoor Activities Cancelled

The City of Toronto announced that all CampTO outdoor field trips and registered outdoor programs scheduled for Wednesday have been cancelled, postponed, or moved indoors where possible because of deteriorating air quality.

Heat Warning Remains in Effect

Toronto also remains under a heat warning.

The temperature is expected to reach 33°C on Wednesday, with humidity making it feel closer to 36°C. Environment and Climate Change Canada warned that the combination of extreme heat and wildfire smoke significantly increases health risks, particularly for vulnerable individuals.