A yellow fog advisory is in effect for St. Thomas, Ontario, as dense freezing fog creates dangerous driving conditions on the morning of March 4, 2026. Environment Canada issued the alert at 5:08 AM, warning residents in St. Thomas, Aylmer, and eastern Elgin County about near-zero visibility that could make travel hazardous.
Visibility was recorded at only 0.4 kilometres at the London International Airport station just before 6:00 AM. Because this is freezing fog, moisture in the air can freeze as soon as it touches the ground or vehicles, which may cause roads and sidewalks to become slippery during the morning commute.
Drivers and school bus operators should allow for extra travel time and maintain a safe distance from other cars on the road. It is important to use low-beam headlights and be prepared for visibility to drop suddenly without warning while driving through the region.
The patches of fog are expected to disappear as the morning goes on. Residents are encouraged to keep an eye on local weather updates until the conditions improve later on March 4, 2026.
