Smoke levels spike across GTA Saturday as wildfires continue burning in northwestern Ontario
Air quality remains "very poor"; afternoon showers may temporarily clear smoke before it returns Saturday night.
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Heavy smoke is once again blanketing the Greater Toronto Area as an orange air quality warning remains in effect for Saturday, July 18, after smoke drifted south from wildfires in northwestern Ontario.
Environment Canada issued the "very poor" air quality warning and forecasts about 10 to 20 millimetres of rain in Toronto with a risk of thunderstorms in the morning or early afternoon. Showers could "help sweep out" the smoke temporarily, though the smoke may return Saturday night. A high of 27°C is expected, but will feel closer to 36°C with humidity.
As of 7 a.m. Saturday, air quality varied across the region: Brampton at 117 micrograms per cubic metre (μg/m³), Mississauga at 91 μg/m³, Oakville at 121 μg/m³, Oshawa at 26 μg/m³, and Toronto ranging from 85 to 114 μg/m³. Oshawa's warning was lowered to yellow, though smoke levels were expected to increase later in the day.
Environment Canada urged residents to limit time outdoors during heavy smoke, noting that seniors, pregnant people, young children, people who work outdoors, and those with existing health conditions are at higher risk. Symptoms may include headaches, eye and throat irritation, wheezing, or chest pains.
The facts
What air quality warning is in effect for Toronto on July 18, 2026?
An orange air quality warning for 'very poor' air quality is in effect for Toronto on Saturday, July 18, 2026, due to smoke drifting south from wildfires in northwestern Ontario.
What rainfall is forecast for Toronto on July 18, 2026?
Environment Canada forecasts 10 to 20 millimetres of rain in Toronto on Saturday, July 18, 2026, with a risk of thunderstorms in the morning or early afternoon.
What air quality readings were recorded across the GTA on July 18, 2026 at 7 a.m.?
At 7 a.m. on Saturday, July 18, 2026, air quality measurements were Brampton at 117 μg/m³, Mississauga at 91 μg/m³, Oakville at 121 μg/m³, Oshawa at 26 μg/m³, and Toronto ranging from 85 to 114 μg/m³.
Who is most at risk from heavy smoke exposure?
Seniors, pregnant people, young children, people who work outdoors, and those with existing health conditions face higher risk from heavy smoke exposure, according to Environment Canada.
