The unpredictability of the ice is coming in different forms this season.
Piles known as ice shoves have been building along Lake Simcoe, and they're posing an especially serious risk to snowmobilers.
Thousands of ice fishers in their huts and vehicles know the conditions change, often in a flash.
"I prefer to have my float suit on for warmth and safety. You have to be cautious of those pressure cracks," says Beeton resident Trevor Caruana.
Pressure cracks are not only an issue out in the middle of the lake. Piles of ice are also showing up on the shores, a phenomenon known as ice shoves. It happens when the ice expands, breaks up, and then comes to a rest.
"We cut it into manageable pieces, and then we move it away from the opening so people can get their four wheelers, ATVs or snowmobiles through," says Donny Crowder of Hot Box Huts.
The wall of ice in Churchill is too high and long, making it difficult to get out of the lake, which is why Crowder cuts his way through it.
"There are safety issues with ice like this. Sometimes they heave under the ice, and people can't see them."
York Regional Police's marine unit is also keeping an eye on the situation and talking to people on the lake.
