Environment Canada released a yellow‑level fog advisory covering Toronto and portions of the eastern Greater Toronto Area on Monday, August 31, 2026, extending into Tuesday, September 1, 2026. The warning follows a rapid rise in humidex values toward 40, coupled with thick fog that has reduced visibility to near zero in the affected regions.
The advisory applies to the city of Toronto as well as the surrounding communities of Pickering, Oshawa and the southern part of Durham Region. Meteorological officials noted that the combination of high humidity and fog has created conditions where drivers and pedestrians may encounter extremely limited sight lines, prompting the issuance of the yellow‑level warning.
Residents are advised to exercise caution while traveling, particularly on major roadways and at intersections where reduced visibility can increase the risk of accidents. The advisory also signals that the dense fog is part of a broader pattern of weather for early September, which includes elevated humidex readings and a heightened chance of scattered showers and thunderstorms across the area.
The current situation marks the start of September under unusually foggy conditions for Toronto. While the advisory does not impose mandatory travel restrictions, it serves as a notice for the public to remain alert and adjust driving habits accordingly. The advisory will remain in effect until conditions improve, with Environment Canada monitoring the fog and humidity levels closely throughout the advisory period.
Authorities continue to track the evolving weather, noting that the humidex near 40 reflects a significant heat and moisture load that can exacerbate fog formation. The advisory will be updated or lifted as visibility and humidity metrics return to safer levels.