Toronto’s Air Quality Ranked Worst In The World As Heat And Smoke Trigger Health Warnings
Adedokun Waliyu
3 min read
Toronto is facing another day of dangerous air quality and oppressive heat, with Environment Canada issuing an orange air‑quality warning Wednesday morning as wildfire smoke from northwestern Ontario continues to drift into the region.
As of 11 a.m. ET, IQAir’s world air quality ranked Toronto in the top spot ahead of Kinshasa (Congo), Delhi (India) and Dubai (United Arab Emirates).
On top of the continuing yellow heat warning, Environment Canada issued an orange air quality warning, the agency’s high‑impact tier, at 8:21 a.m., citing “very poor air quality and reduced visibility” caused by smoke from the large wildfires.
The agency says conditions may improve Friday morning, but until then, everyone’s health is at risk, regardless of age or medical history.
The warning urges residents to limit time outdoors, reschedule outdoor sports or events, and monitor for symptoms such as eye, nose and throat irritation, headaches, mild cough, wheezing, chest pain or severe cough. Those most vulnerable — including older adults, pregnant people, infants, young children, people with chronic conditions and outdoor workers — are advised to avoid strenuous outdoor activity.
Air‑quality risk levels are expected to worsen steadily through Wednesday, reaching the “very high” category by evening. According to Environment Canada:
Risk levels rise from moderate late Wednesday morning to high by late afternoon.
By 8 p.m., the risk reaches 8–10, considered high.
From 9 p.m. onward, levels exceed 10+, classified as very high, and remain elevated overnight into early Thursday.
High‑risk conditions continue through Thursday morning, with levels gradually easing later in the day.
In Toronto, expect a forecasted high of 33°C and a humidex near 39 on Wednesday. 680 NewsRadio weather specialist Denise Andreacchi says the combination of heat and smoke is especially dangerous because it forces the body to work harder to cool down while also irritating the lungs.
Wednesday will bring sun and cloud with a chance of showers, though any rainfall is expected to be brief and scattered. Winds from the west‑northwest at 15 to 30 km/h may help shift smoke later in the day, but air quality is expected to remain poor until conditions improve upstream.
Overnight, Toronto will see partly cloudy skies, lingering smoke, and a low near the low 20s.
The City of Toronto has cancelled FIFA Fan Fest and Nathan Phillips Square viewing parties of the semifinal match-up between England and Argentina on Wednesday
All wading pools have also been closed but all outdoor pools remain open.
Thursday is expected to be mainly sunny, with winds from the west at 15 to 30 km/h. Temperatures will reach the low 30s, with a humidex in the mid 30s. Air quality may improve slightly if winds strengthen, but forecasters say smoke could still drift into the region depending on wildfire activity.
Friday will feature sun and cloud with a chance of showers, followed by more measurable rain Friday night and early Saturday. That rainfall is expected to help clear smoke and ease humidity as Toronto transitions back to a more seasonal weather pattern.
Saturday will bring scattered showers and an early risk of thunderstorms, with temperatures returning to the mid 20s. Sunday looks calmer, with sun and cloud and a high near the upper 20s.
