As the city goes from record-breaking bone chilling temperatures to more seasonal weather in the coming days, Toronto police are warning the public against venturing out on natural bodies of ice.

"No ice is safe ice," Const. Corey Smith of Toronto Police Service's marine unit said. "Just because the ice looks like it's fine there's lot of cracks involved in the ice surface." 

Smith says people walking out onto ice is a big concern for police now that frosty winter weather has arrived.

Police say they saw 20 to 30 people walking out on the ice at Toronto's harbour on Friday. The harbour has been frozen for the first time in years after days of temperatures well below zero.

Walking onto ice covered natural bodies of water is risky because ice works a lot like tectonic plates, Smith says.

Const. Corey Smith

Const. Corey Smith of Toronto police says ice on natural bodies of water remains unsafe at any temperature. (CBC)

"If they move around, you could find weak spots where even though the ice is thick, it could open up and you could end up falling into the water," he adds.

Despite the number of people walking out onto the ice on the Toronto Harbour, police have noticed that there's open water on the east end of the harbour. The risk will also likely grow once temperatures rise.

"It only takes a day of really bright sunshine on a warm day to severely compromise the thickness and structural integrity of the ice that's there," he says.

City rinks remain safer way to skate

Your best bet for staying safe skating during the winter remains skating at one of the dozens of city skating rinks.

At Grenadier Pond, one of Toronto's most popular skating spots, the city says a team of ice engineers inspects the ice daily and flags the ice when it's unsafe to skate.

"For the most part it's against the municipal code to skate on the lake or in ponds or parks, but where possible, where we're able to test this ice and ensure it's safe, folks are invited," said Matthew Cutler, spokesperson for Toronto Parks and Recreation. 

For those who take the risk to go out on unsafe ice on bodies of water, however, Toronto police say they're prepared.

"l wouldn't say we mind doing them. This is what we're here for," Smith says. "This is why we train, what we train for and have the equipment we do."