Extra caution is being urged for mariners travelling along lower Lake Huron and the St. Clair River this week.
Environment Canada Meteorologist Gerald Cheng said dense fog has developed along the waterways, which is creating dangerous conditions.
"That's the problem with early summer, when the lakes are still pretty cold," said Cheng. "Temperatures are situated around 13 C to 18 C in Lake Huron waters, whereas for us over land it's in the high 20s. The dew points are quite high as well, it's very humid, around 18 C, so when you have the dew point, that humid air mass and it's being cooled -- that's why we have fog."
He said fog is always concerning for people on the water.
"You can't see. People would have problems sailing their boats because you could get into collisions. So, we want people to be careful out there," he said.
Cheng said if you do go out on the water, go slow because fog banks can develop suddenly.
Fog shrouded Blue Water Bridge July 3, 2019 (BlackburnNews.com photo by Dave Dentinger)