Sarnia fire and police are asking residents not to venture out on thin ice.
Fire Life Safety Educator Mike Otis said the ice isn't thick enough to be skating on at this point.
"We're hoping that people never go on the ice unless they know it's absolutely safe to do so," said Otis. "It takes several days of below freezing temperatures to even freeze ice to a safe level."
Otis is aware of people already venturing out onto Lake Chipican in Canatara Park.
"One of our officers saw it for themselves and actually said when they sent the picture that it wasn't even frozen yesterday and then the next day they're skating on it, so it's very unsafe."
Sarnia police Cst. John Sottosanti said the weather has been too inconsistent and there's no guarantee the ice is able to hold a person's weight.
"Obviously, if you're going to be going onto the ice you should be testing it out by the proper means, which is normally by drilling holes and seeing the actual depth of the ice," said Sottosanti. "Anything less than seven centimetres, people are asked to keep off the ice, while ten centimetres individuals can walk on it, 12 centimetres small vehicles can be placed on the ice and then anything above 20 centimetres larger vehicles."
Sottosanti said conditions could become especially dangerous with milder temperatures forecast over the next few days.
"You're not only jeopardizing your life, you're jeopardizing the life of first responders who have to go out there and try and get the person out if someone does fall through."
Sottosanti said fishing huts and other property may also fall through if the ice is too thin.
The Town of Petrolia issued a notice Wednesday afternoon cautioning people against skating on Bridgeview Park Pond.